CA1302572C - Handwritten keyboardless entry computer system - Google Patents

Abstract

Abstract of The Disclosure A keyboardless entry computer system includes a transparent input screen that generates positional information when contacted by a stylus, and a display screen mounted physically below the input screen such that a character that is displayed can be seen below the input screen. The system includes a computer that has been programmed to compile the positional information into Strokes, to calculate Stroke characteristics, and then compare the Stroke characteristics with those stored in a database in order to recognize the symbol drawn by the stylus. Key features of the system are:
(1) transparent position sensing subsystem; (2) underlying display on which to mimic drawing of sensed positions and to show characters or symbols; (3) means to convert sensed positions first into plotted Points and then into recognized characters or symbols; and (4) means to "learn" to associate sensed input positions with a character or symbol.

Description

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The present invention relates generally to a keyboard-less input system to a computer, and when combined with a central processing unit, to a keyboardless entry computer system. More particularly, the present invention relates to an information storage, manipulation and transfer device on which text, data, computer commands and functions are entered by writing alphanumeric or any other characters and symbols by hand with a penlike stylus on an Input/Output (I/o) screen.

Large amounts of information and sophisticated applica-tions software are now available on conventional keyboard com-puters. The utility of this information and of application software could be greatly increased if text and data could be : L3~

entered and applications software manipulated by writing in a normal fashion directly on a flat display. Thus, there is a need to allow the utility of computer technolo~y to be extended for use by non-keyboard oriented individuals. There is also a need for a portable computer system that is liqhtweight, reli-able, accurate, lnexpensive and permits use while standing or walking. One way to reduce expense and size and increase utility is to employ a keyboardless entry system, such as a touch screen. However, this type of input device does not easily allow accurate detailed input within a real time framework with high resolution in a mann~r which is familiar and natural to the user.
Many positioning technologies can be used to meet the requirements of the position sensing input technology.
Essentially these requirements include accuracy, resolution and speed. The technologies include: mechanical, electrostatic, electromagnetic, acoustic, optical, and nertial. The desire in this system is to have its use as similar as possible to writing with pen or pencil on paper. One problem is proximity -- a pen on paper only leaves a trail when actually in contact.
Many of these technologies require an additional "pen down"
sensor which is awkward to use in many commercial pens.
Another problem is writing angle ~- a pen leaves the same trail independent of writing angle. Many of these technologies have the position detector displaced from the pen tip, so pen angle causes erroneous displacements. Beyond these general problems, each technology has numerous advantages and disadvantages in (1) the pen: size, weight, shape and whether it needs to be powered and/or wired, and (2) the wriking surface:
transparency, smoothness, "feel", and whether or not physical contact is needed (as opposed to pressure transmitted through overlaying sheets of paper).

`~ ~3~2g~ ., A number of self-contained devices for viewing and processing large amounts of in~ormation are known. Most employ optical, magnetic or solid-state electronic storage means to store data. Illustrative of this body of art is U.S. Patent 4,159,417 to Rubincam which discloses a portable electronic book configured to provide selective page by page call-up of large amounts o~ digital data and displays it on a flat, solid-state screen. The preferred embodiment in the Rubincam patent uses an insertable holographic card, which may contain several hundred pages of text in digital form, as the main storage means. Rubincam's device, however, does not allow new information or text to be entered or manipulated.
In U.S. Patent 4,016,542 to Azure an electronic data collection system is disclosed which employs a solid state Ran-dom Access Memory (RA~I) for its primary memory. This patent, which discloses a conventional keyboard for data entry, is di-rected to a hand-held portable data storage and transmission system, as well as an LED display and various Input/Output (I/O) connectors.
U.S. Patent 3,487,731 to Frank discloses a means of converting handwriting into character data through the use of a computer system. The disclosed invention is based on matrix pattern matching and does not employ any coincident display technology.
U.S. Patent No. 4,491,960 to Brown shows a handwritten symbol recognition system in which an array of image Points, in the form of a raster line sampling, is converted into segment-oriented lists which are filtered and compressed to obtain topologic features which are then analyzed with a logic tree decision mechanism.

U.S. Patent No. 4,262,281 to Buckle et al. discloses a handwriting recognition device. ~he disclosed embodiment is for use with a host computer and does not employ coincident display technology.
U.S. Patent No. 4,475,239 to Van Raamsdonk discloses a text editing apparatus. The '239 patent calls for the use of paper as a medium for the entering of editing functio~s and requires a conventional keyboard for the inputting of text.
U.S. Patent 4,521,909 to Wang shows a dual level pattern recognition system. The system is designecl for use with an optical instrument.
U.S. Patent 4,520,357 to Cast~erry e al. discloses an electroscopic information display and entry system with writing stylus. The disclosed embodiment does not claim to have the speed or accuracy to enable handwritten character recognition.
Additional prior art which discloses portable elec-tronic devices that provide large amounts of various types o stored information include U.S. Patents 4,218,760 to Levy;
4,4115,486 to Laine; and 3,932,859 to Kriakides et al. The Levy and Kriakides et al. patents pertain to electronic dic-tionaries, while the Laine patent discloses a programmable television reminder system. None of these devices disclose the use of a handwritten input.
In U.S. Patents 4,071,691, 4,129,747, 4,198,539, 4,293,734, 4,302,011, 4,353,552, 4,371,746 and 4,430,917 to William Pepper, Jr. various methods or machine-human interfaces using finger touch are disclosed. The preferred embodiments in each of these inventions lack sufficient speed and resolution to allow handwritten character recognition with a stylus and are designed for other purposes. U.S. Patent 4,318,096 to Pepper ~3~
teaches ~he use of a conductive stylus. The '096 pate~t per-tains to graphic design and allows line width and line intensity to vary by applying pressure on the stylus with the results displayed on a conventional CRT screen. U.S. Patent 3,699,439 -to Turner and U.S. Patent 4,055,726 to Turner et al. discloses two methods for electronic position sensing through the use of a probe.
It is an ob;ect of the present invention to provide a novel apparatus and method for recognizing handwritten characters.
According to one aspect of the present invention there is provided an apparatus for recognizing Handwritten Symbols and respectively displaying Handwritten and Font Symbols and executing Editing Functions or other commands on a screen comprising:
(a~ A visual display screen having the graphic capability to display Font Symbols and means to execute Editing Functions;
(b) Hand-held means to wrlte or draw Handwritten Symbols on or over said screen;
(c) Means to display a true representation of the Handwritten Symbols on said screen as they arP created;
(d) Digitizing means to sense the position of said hand-held means and to convert the same into a series of electrical signals defining position, size and shape of each Handwritten Symbol;
(e) Means to compare predetermined characteristics of each digitized Handwritten Symbol with a database of predetermined characteristics of Font Symbols and Editing Functions to assess the identity of each Handwritten Symbol;
(f~ Means to (i) convert each Handwritten Symbol to an Editing Function or other commands or a predetermined Font Symbol and (ii) execute the Editing Function or other commands or display the Font Symbol on the screen in close proximity to the scr~en area in which the corresponding Handwritten Symbol was originally entered, as the case may be;

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(g) Means to display predetermined combinations of Font Symbols in the form of te~t or forms on said screen, whereby Handwritten Symbols can be used to input information to complete a form, to adit a predetermined text, or both, as the case may be; and (h) Means operative upon execution of a predetermined command to create a window on said screen, free of text or other information, for entering Handwritten Symbols.
According to another aspect of the present invention there is provided a microprocessor-based process for recognition, translation and display of Handwritten Symbols and execution of Editing Functions and other commands comprising the steps of:
(a) Creating a personalized database for each individual user of the process by having the user initially input a Handwritten Symbol for each character corresponding with a Font Symbol to be displayed or Editing Function or other con~and to be executed;
(b) Determining a unique set of Stroke characteristics to characterize each such symbol and storing it in the database;
(c) Writing or drawing Handwrit-ten Symbols on a computer screen with a stylus;
(d) Digitizing each Handwritten Symbol to identify the ~, y coordinates of a multiplicity of Points into strokes defining the Handwritten Symbol;
(e) Processing the digitized characteristics of each Stroke of a Handwritten Symbol to determine the predetermined characteristics of the Handwritten Symbol;
(f) Each of steps (b) and (e) comprising a determination of the (i) length of the stroke, (ii) average slope of the stroke, (iii) tha stroke centroid's height above the base line, (iv) rate of change in the slope of Stroke and (v) comparison of the location of the centroid of each Stroke with the centroid of the Handwritten Symbol.

- 5a -~L3~25~2 (g) Searching the database to find a "hit" a perfect or the closest correspondence to the chara~teristics of a Font Symbol;
(h) Displaying the Font Symbol or performing the command most closely associated with the "hit" characteristics.
According to yet another aspect of the present invention there is provided a method for recognizing handwritten symbols, comprising:
providing a display screen;
writing a handwritten symbol over at least a portion of first area of said display screen;
digitizing said handwritten character to provide a digitized symbol;
displaying an image of the handwritten symbol on said display screen in at least a portion of said first area as it is written;
correlating said digitized symbol with at least one of a plurality of predetermined symbols including a plurality of Font Symbols and a plurality of Editing Symbols, by comparing characteristics of said digitized symbol with stored characteristics of at least some of said plurality of predetermined symbols, to provide one of said plurality of predetermined s~mbols as a Designated Symbol which is correlated with said Handwritten Symbol;
displaying a computer-generated symbol on said display screen when said Designated Symbol is a Font Symbol;
executing at least a first of said plurality of editing functions when said Designated Symbol is a first of said plurality of Editing Symbols, and executing at least a second of said plurality of Editing Functions when said Designated Symbol is a second of said plurality of Editing Symbols.
According to still yet another aspect of the present invention there is provided in a device for processing information which includes a display device and a device for recognizing digitized symbols, for displaying recognized - 5b -characters on sai~ display device and for executing commands corresponding to recognized command symbols, a method for inputing symbols to said device comprising:
providing a digitizer for digitizing a Handwritten Symbol and providing a digitized symbol to -the device for recognizing, said digitizer and said display device positioned one over the other to permit viewins of said display while looking at said digitizer; and creating a window on said d~splay device, upon execution o~ a predetermined command, for entering at least two handwritten symbols.
In still yet another aspect of the present invention there is provided in a device or recognizing and displaying handwritten symbols, an apparatus, comprising:
a display; and means, coupled to said display, for creating a window on said display for entering at least two handwritten symbols~
In still yet another aspect of the present invention there is provided a method for recognizing symbols and editing text comprising:
providing a computing device which includes a display, said display having apparatus for providing output signals, each output signal indicative of a plurality of successive positions on said display selected by a hand-held stylus;
receiving said signals in said computing device;
using said compu~ing device to recognize at least some of said output signals as corresponding to at leas-t some of a plurality of font symbols;
using said computing device to recognize at least some of said output signals as corresponding to at least some of a plurality of editing symbols;
displaying a predetermined symbol on said display when said recognized symbol is a font symbol; and executing an editing function when said recognized symbol is an editing symbol.

- 5c -~30~$72 Preferably, the present keyboardless computer system has the ability to recoynize and display Handwritten Symbols and cause the computer to display Font S~mbols and, if desired, to execute editing functions pursuant to Editing Symbols, quickly, easily and at reasonable cost.
Preferably, a computer housing is provided with a flat display panel on which a user may "write" with a stylus, a capability to recognize Handwrit~sn Symbols written on the panel with the Stylus and convert them to displayed Font Symbols and/or to execute Editing Functions with Editing Symbols, all with a minimum of technical complexity for the user.
It is also preferred that once the keyboardless, portable computer is loaded with the desired information and applications software, information and software can be used and responded to without requiring skills or knowledge related to state-of-the-art computers or other data source.
The ease-of-use of the input technology of the present invention enhances the utility of the computer for keyboard oriented individuals. The portability of the present device also allows it to be used in applications and settings in which portable keyboard computers are awkward, difficult or impossible to use. For example, a multiplicity of - 5d -~3~
, ~ `~,, ,) blank, fully or partly completed forms may be stored in the portable computer memory. In a hospital, "sheets" of patient data can be stored in the memory o~ the portable computer, called up by a nurse as the nurse makes rounds and relevant data, such as blood pressure, temperature, etc., can then be entered manually with a stylus. These corrected or expanded forms can then be down-loaded into a central computer memory.
The re~uirements of the position sensing input tech-nology are accuracy (Point to Point), resolution (absolute position) and speed (Points per unit time) to adequately define the written Stroke for reco~nition analysis. For the recognition apparatus and methods presently used, as described below, the present minimum re~uirements are: accuracy of .005 inch, resolution of .015 inch, and speed of 150 Points per second. This accuracy allows a l/4" high writing line with over 10 raw input Points along a Stroke of a small letter. The resolution provides positioning of the symbol to within two pixels on a present display of 640 pixels to 9 inches. The speed permits about 50 raw input Points for a rapidly written single letter (l/3 second).
One embodiment of the present inventlon comprises a transparent input screen. As the user writes alphanumeric or other characters or symbols on the input screen, the character is represented as a stream of Poi~ts emulating written input with pen on paper. Once the discrete alphanumeric and other characters or symbols are complete, they are translated into com-puter text or computer commands that can be displayed on a dis-play screen at a location that is preferably beneath the area on the input screen where they were entered. The embodiment also comprises a pattern reco~nition algorithm which allows the translation of any written character or s~bol, such as ideographs and scientific symbols, into computer text.

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- , _ In a particular, presently preferred embodiment, a keyboardless computer according to the present invention is con-figured as a manipulation and display device comprising a trans-parent touch screen and associated electronics placed over an 80 column by 25 line or larger display screen; a stylus for entry of data; a microprocessor and storage means; artificial intelligence/pattern recognition software and editing software;
and a battery power system; and other I/O means.
As used herein, "Handwritten Symbols" are any symbols capable of being handwritten and having communicative effect.
By way of example, and not limitation, numbers, letters, "Kanji" (Japanese ideograms) or other language symbols, editiny symbols and engineering, scientific, architectural and mathematical symbols are Handwritten Symbols. Other examples of Handwritten Symbols are free-hand drawings or signatures or any other such written information uniqu~ly configured by a particular writer. Handwritten Symbols may also include Editing Symbols (defined below).
As used herein, "Font Symbols" are computer-generated symbols which are displayed in a predetermined font format. By way of example and not limitation, alphanumeric symbols may be Font Symbols and displayed in numerous font formats. Japanese or Chinese "ideograms" may also be Font Symbols, as may be engineering, scientific, mathematical, architectural or other such characters. Other examples of Font Symbols include any form which can be stored and displayed by a computer, e.g., a drawing of a car or a house.
As used herein, an "Editing Symbol" is a symbol (such as a caret, horizontal line, short vertical line, long vertical line, etc.) which is intended, when recogni~ed, to cause the computer to execute a particular Editing Function (defined below), such as insert test (caret), delete text (horizontal line), delete a letter (short vertical line) or move a maryin (long vertical line), to list a few representative examples.
"Editing Function" means any computer-generated text editing operation, such as by way of example and not limita-tion, insert text, delete text, move text and substitute text.
Some primary Editing Functions are listed on paged 40 and 41 below.

Thus, t.he present inven-tion provides improved methods and apparatus for providing a keyboardless computer on which usual computer functions are per-formed by writing in a normal manner with a pen-like stylus on an input screen placed directly over a flat display.
The keyboardless computer provided is ideally config-ured for use by non-keyboard oriented individuals, by keyboard individuals for whom the utility of the computer is enhanced, and in various settings and applications in which keyboard entry is awkward or impossible.
Preferably, means are provided whereby computer-based information and applications soft-ware can be loaded into a portable device for later viewing, man1pulation of text and data, and adding new text and data in a normal handwriting mode. Thereafter the user may transmit this computer text to another computer, a similar device, an external electronic storage device, a hard copy printer, or through a telecommunications system. It is al.sn nrP~r~rrerl ~h~
the present invention provides acomputer capable of recognizing Handwritten Symbols with a high degree of accuracy and of "learning" individual styles of handwriting.

~3~25~2 Preferably, the p~esen~ invention also provides a portable keyboardless computer in which data and commands are input with the use of a s-tylus.
Embodiments of the present invention will now be described by w~y of example only with reference to the accompanying drawings in which:
Fig. 1 is a schematic system block diagram of a portable handwritten, keyboardless entry computer system;
Fig. 2 is a perspective view of the housing containing the operating elements of the sys~em shown in Figure 1;
Fig. 2A is an enlarged portion of Fig. 2, with parts removed to show the positional relationship between the touch input screen and the display screen.
Fig. 3 is a schematic diagrammatic view of the input screen, stylus and associated electronics;
Fig. 4 is an overall schematic system block diagram of the apparatus of a keyboardless entry computer syste~;
Fig. 5 is a schematic block diagram depicting the movement of data within the system when modified by handwritten characters and commands;
Fig. 6 is an overall system block diagram depicting the hierarchy of software used to operate the system;
Fig. 7 is a generalized block diagram of ~he charac-ter and pattern recognition algorithm.
Figs. 8A and 8B together are a detailed block diagram of the patter recognition algorithm.

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Fig. 9 is a schemat~c block diagram of the Stroke characterization subroutine.
Fig. 10 iS a top plan view of a screen illus-trating the "initializ.ing" of the database for Handwritten Symbols.
Figs. LlA through llI are a series of top plan views of screens depicting the operation of a text editing system.

- 9a -Figs. 12A through 12G are a series of top plan views of screens depicting the operation of a data entry system.
Fig. 13 is a generalized block diagram o.~ the Linus Editor.

With reference now to the figures, wherein like numer-als indicate like elements throughout the several views, and in particular with reference to Fig. 1, an overall block diagram of a portable handwritten, keyboardless entry computer system 10 is depicted. The complete computer system is encased in a housing 12, indicated graphically by the dashed line, and includes a con-ventional, general purpose digital microcomputer 14, described in greater detail hereinbelow. Input information is provided to microcomputer 14 by stylus 16 "writing" on writing or input screen 18. Stylus 16 (Fig. 2) is connected to the computer of system 10 with wire 17 (Fig. 2). As stylus 16 "writes" on input screen 18, a plurality of locating signals representative of a plurality of corresponding positional coordinates are transmitted to microcomputer 14. Microcomputer 14 has been programmed in accordance with a computer program described hereinbelow, to recognize the stream of locating signals and to store these signals in a computer memory. The programmed microcomputer 14 also provides a corresponding plurality of display signals to a display screen 20. Both input screen 18 and display screen 20 are described in greater detail hereinbelow.
Referring now to Fig. 2, there is shown a perspective view of keyboardless computer system 10.
Keyboardless computer system 10 is con-tained in housing 12, which is a rectangular enclosed casing having a sloped top surface 22 with a multi-line, solid state : .

~ 2~72 display area 24. Input screen 18 is depicted in Fig. 2A as be-ing positioned over display screen 20. In this example, display screen 20 displays a plurality of horizontal lines 25 with the following indicia:

Name Address Handwritten entries are made above each line 25. The distance or space between two lines 25, denoted 26, is used by the system to normalize all distances, and lines 25 themselves serve as a reference axis or base line~
Below display area 24 on top surface 22 is a key input section 26 comprised of a plurality of "Softkeys" 28.
Softkeys 28 can be programmed by the operator for any purpose, such as to enter computer commands. Exemplary commands for Softkeys 28 are "store," "recall," and "delete." In addition, Softkeys 28 can be used to switch between different programs or between modes (e.g. data entry mode and edit mode). However, Softkeys 28 are optional and are used to supplement the input obtained by handwriting the entries. Stylus 16, used for writing input data and commands in display area 24, also is used to activate the selected Softkey 28. An ON-OFF switch 30 is positioned on the side of housing 12 adjacent to Softkeys 28. A data output or peripheral connector 31 is located on the upper right side of housing 12.
Input screen 18 can be a conventional resistive type touch screen in which a voltage is applied to the screen edges and a stylus detects the voltage at the touched location. The writing surface is a transparent material, typically glass, coated with a thin, uniform, conductive layer (presently, vacuum deposited indium tin oxide). Vertical bus bars or conducting strips (not shown) are used along the two sides to ~3i~2~72 apply the reference voltage to determine the "X" coordinates of the stylus position and horizontal bus bars or conducting strips (not shown) are used along the bottom and top to apply the reference voltage to determine the "Y" coordinates of the stylus position. In this embodiment, stylus 16 is merely an electric probe that, when physically in contact with the conductive layer, detects the local voltage at the Point of contact, which will vary with the distance from the conducting strips or bus bars. With the origin at the Point of voltage application, the X,Y coordinates are inversely proportional to the impressed voltage. Stylus 16 must make good contact to minimize adding resistance that would lower the voltage detected, and thus add an erroneous distance increment. In a presently preferred embodiment, a soft graphite tip is used. The voltage is conducted from the pen through a wire, such as wire 17 in Fig. 2, to an analog to digital converter for use in the computations described below. The stylus may be a charged "pen" as described herein, a light pen as is well known in the art, or any other hand-held device which can outline Handwritten Symbols on a screen.
An example of a conventional electrostatic screen is disclosed in the aforementioned 4,318,096 Pepper patent. This Tesistive type screen has the advantage that the inference caused by the user's hand touching the screen is minimized.
Both horizontal and vertical position sensing is provided by alternately switching the voltage impressed on a conductive layer between the pairs of horizontal and vertical bus bars by an interface and multiplexer controlled by a microcomputer or microcontroller. In one commercially available input or touch screen, the bus bars are broken into a series of short strips with diodes to prevent the hs)rizontal strips from shorting out vertical strips and vice versa. This technique is used in a commercially available touch screen from Touch Technologies of Annapolis, MD. and Flographics of Oak Ridge, Tenn.
Referring now to Fig. 3, an alternate embodiment of a low power position sensing novel input screen 33 is described in greater detail. Input screen 33 is also for determining an X,Y position on an electrically resistive plate 34. A stylus 35 containing a voltage source, such as battery 36 or a voltage transmitted to stylus 35 from an external source such as the system power supply, is used to touch screen 34 and apply a voltage at the touched position. When the touched position is charged by stylus 35 with a positive voltage with respect to a plurality of plate measurement Points 37, the voltages at these Points will vary with the distance to the pen position, such as position X~, Yl, indicated at 38. These voltages are sequentially measured in the X and Y directions by using conventional means, such as disclosed in the aforementioned prior arts patents. In Fig. 3 these means are a conventional interface/multiplexer 42. A conventional Analog-to-Digital converts 43 converts the detected voltages into a digital signal. A microcontroller 44 receives the digital signal, performs standard checks to ensure the signal's numerical value is "valid" (e.g. is within the possible range of voltages), and then converts the voltages to X and Y distances in the manner described herein. Microcontroller 44 is conventional, but could be replaced by a system computer. Microcontroller 44 provides a digital signal representative of the X and Y distances to measuring Point 3g to an output port 46. Port 46 can be a conventional RS 232 port. Alternatively, microcontroller 44 could translate Point Xl, Yl to any other reference Point, such as a Point on base line 25 (Fig. 2).

5~72 As long as there is no contact by stylus 3~ at posi-tion 38 or any other position on plate 34, no current flows and power consumption is minimal. An incident measurement of the voltage at the measurement Points may occur by using ramped voltage at the positioning Point and timing when the measuring Point voltage exceeds a preset back voltage.
The scope of this invention covers the following options for the input or touch screens 18 and 33: resistive plate 34 or its e~uivalent for screen 18 can be transparent or translucent and the position Point can be made by a stylus or a finger of the user, or a connecting Point of an overlapping conductive screen (such as the commercially available touch screens from Touch Technology, Annapolis, MD.). Input screens 18 and 33 can be a physical solid surface which is transparent or translucent and can be glass or plastic such as Mylar. The surface can be coated with a conductive/resistive substance like indium tin oxide. ~ther physical surfaces can use sound or electromagnetic radiation transmission from the touched position to a reference Point or Points and the distance is determined by the time delay or phase shift. Alternatively, input screens 18 and 33 can use an ethereal or geometric surface defined by an electromagnetic, optical or sonic field.
Position detection can be accomplished with electrical contact closure by resistive, capacitive or inductive coupling, remote sensing by sonic, electric or magnetic fields or by light (UV, IR, or microwave) scanning.
The advantages of the low power position sensing input invention over other such screens are: 1) the invention makes stand-by power requirements minimal; 2) the invention eliminates distortion due to opposing parallel "bus" bars in conventional touch screens; and 3) when a ramped voltage is employed, the - -~301~572 invention eliminates the need for an A/D chip which is a major cost factor in state-of-the-art touch screen technology.
The coefficient of friction of the screen 18 is desir-ably selected to be "rough" enough to offer some resistànce to the movement of stylus 16 on the screen. If the screen were too smooth, the stylus would slide too easily and would be difficult to control.
Reference is now made to Fig. 4 which discloses an overall system blocX diagram of the major electronic circuitry used in the preferred embodiment of the present invention.
Microcomputer 14 includes a microprocessor 50, interconnected to a plurality of other electronic elements by means of data path or bus 52. A Read-Only-Memory (ROM) 54 which is programmed with the operating and application programs and a battery powered Random Access Memory (RAM) 56 is connected for bidirectional data flow onto bus 52. Microprocessor 50 may be a conventional single-chip eight-bit or sixteen-bit device which functions to execute the fixed control programs residing in ROM 54, and further receives control programs from and provides control signals to the other electronic elements via bus 52. Microprocessor 50 may be of the type commercially designated Z80*(manufactured by Zilog Microcomputers of Cupertino, California), of a type 8088*device (manufactured by Intel Corp. of Santa Clara, California) or any similar or more powerful microprocessor. ROM 54 may be of the type 2564*or 4764*, both manufactured by Texas Instruments of Dallas, Texas.
The storage capacity of RAM 56 is determined in part by the sizes of the application programs, the operating program and the database. As discussed below, RAM 56 may be of the static SRAM or dynamic DRAM type. The primary requirements of RAM 56 are that it have sufficient storage capacity and that it require a minimum of input power.

* Trademark A battery 58, such as a lithium battery, provides power for making the memory of RAM 56 non-volatile for extended periods of time. A battery pack 60 containing the well-known rechargeable types of batteries is used to provide the various voltage levels required by the other electronic elements of microcomputer 14.
Alternately, the storage function of RAM 56 may be served by a non-volatile device which requires no power for main-taining storage, such as an electronically erasable and repro-grammable memory (EEPROM), or devices using magnetic bubbles or capacitance. State-of-the-art disk or tape may also be used or mass storage. Suitable bubble memory devices include types 711G*and 7114*which have storage capacities of 1 megabit and 4 megabits respectively. (Both are manufactured by Intel Corp.).
Furthermore, it is possible to use a single integrated circuit chip which includes microprocessor 50, at least part of ROM 54 and at least part of R.U~ 56.
Also connected to bus 52 is an EI~ RS-232 serial inter-face 62 which provides a means for inputting and outputting data.
Data is provided to bus 52, (usually to RAM 56) by interconnect-ing an external data source to RS-232 port 62 directly to the microprocessor 50 and other elements of the microcomputer 14.
Offloading data from RAM 56 can also be done by microprocessor 50 to an external computer, other data gathering device, a mass data storage device (e.g. floppy and hard disk drives) or an electronic telecommunications system. In like manner data can be communicated through port 62 to a printer (not shown) from interconnecting bus 52.
Stylus 16 is used to write on input screen 1~ and to cause the generation of X,Y coordinate information by conven-tional touch screen interface electronics circuitry. The coor-dinate information is communicated via the bus 52 for control * Trademark ~3~57~:
~ . .

use by system 10. The solid state display 20 consisting of a multi-line display -- illustratively ~0 columns by 25 lines --is interconnected to bus 52 throuyh a display interface 66.
The fundamental requirements for the display are that it be sub-stantially flat and sufficiently thin for use in the present invention. The display may be of the following types: scanning types such as a cathode ray tube, projected types such as a rear-view projector, light emitting array of Points types (e.g., electroluminescent or plasma discharge~ and light blocking array of Points types (e.g., liquid crystal displays, solid state PLTZ or magneto-optical). In addition, it is preferable that the display be compatible with input screen 18 in size, configuration and transparency, and that both be low power consuming types.
The ~,Y coordinates for this invention are input -to keyboardless computer 14 via input screen interface electronics 64 and communicated via bus 52 to microprocessor 50 which executes programs stored in ROM 54 and RAM 56.
The number of Points (i.e., sets of X, Y coordinates) used in defining each Handwritten Symbol and the speed at which Points are identified are important to the practical utility of the invention. It is desirable to use at least about 100 Points per inch and at least about 100 Points per second to define Handwritten Symbols. It is to be noted that the more Points per inch that are identified, the greater the accuracy of the system in identifying ~andwritten Symbols -- however, more Points being identified will slow down the speed of identification and require more computer memory. ~ccoxdingly, a balance will have to be achieved, based on the size (avail-able memory and processing ability) of the computer system and the requirement for speed of response and accuracy. For most ~ ~31~:~5~2 ~

purposes, standards in the range from about 100 Points per inch and per second to about 200 Points per inch and per second will be suitable.
It is also to be noted that the greater the precision of the system in identifying the X,Y coordinates of each Point the fewer the number of Points needed to be identified per inch and per second to accurately identify Handwritten Symbols. Con-versely the less the accuracy, the more Points that are needed.
Point resolution is needed to place Points where intended, e.g., to write an editing symbol precisely between the two characters. Ideally, resolution to a single display pixel is desirable. However, operationally, resolution within two displayed pixels is sufficient for a display with 640 pixels in a nine inch horizontal scanline.
When switch 30 (Fig. 2) is positioned to "power on", the basic display mode is activated and microcomputer 14 (Fig. 4) programmed by the operating system, causes a menu to be displayed on display screen 20 (Fig. 1). The menu presents various software options. A primary software function, editing, functions in a manner similar to conventional word processing software with the difference being that handwritten characters, symbols and commands are interpreted by the system as if they were entered from a conventional keyboard. The system is capable of learning the editing symbols used by a particular writer for functions such as indent, insert, delete, move and reformat and translates those symbols into digital command functions. Optionally, Softkeys 28 (Fig. 2), activated by touching those areas on the input screen with stylus 16, function like conventional hard function keys on a computer keyboard.
The present invention is part~.~ularly adapted for use as an interactive screen editor or word processor. After a ~ ~310 25~ ~

writer retrieves a document by (for example) touching the displayed name of an existing file with the stylus or by writing the name of the file on the screen, all usual editing functions can be performed with stylus entry. When the user wishes to change a displayed character or symbol, he may simply write over the displayed character or symbol and as described hereinbelow the pattern recognitio~ algorithm will translate the written entry into computer text. For example, the editing software allows text to be eliminated by simply drawing a line through it and a conventional caret symbol may be used to change the operating mode to the insert mode. In the insert mode, display screen 20 provides additional space for entry of handwritten characters or symbols which are inserted in the text after the Point where a caret was written in. Text can be moved simply by placing brackets or other user-defined delimiters around a displayed phrase or word and writing a caret or other user-defined symbol in the area of the text in which the user wishes this material to appear. New margins can be set by drawing vertical lines down the side of the displayed text where the new margins should appear.
The basic editor software also allows new documents to be created by simply writing Handwritten Symbols on the screen.
All documents can be stored, changed and communicated in the manner in which these functions are accomplished on a conventional word processing system with the difference that these functions are accomplished with handwritten Editing Symbols on the (optional) screen or by touching the Softkeys with the stylus. The composite text thus produced and stored can be subsequently offloaded through t RS 232 port 62 (Fig.
4) to another computer, a similar device, an external data gathering device or recording device, into a printer or through a telecommunications system.

~3~2~;72 In addition to these major operating modes, a number of ancillary elements and features add to the utility of the present invention. A conventional alphanumeric keyboard (not shown) containing a full set of keys can be connected to a conventional keyboard interface (not shown) to support the entry of alphanumeric characters. An AC/DC power connector may also be used in those applications when portability is not needed and when needed to meet the power requirements of screen technologies such as gas plasma displays and electroluminescent displays.
In actual use the keyboardless computer can function in any application or environment in which handwritten input translated into computer text is useful or necessary. Illustratively, the device can function as a new generation word processor, or for use in fields such as sales, nursing, inventory control, census taking, claims adjusting, to name just a few of the many uses of the invention, or as a general learning and testing device in education. Since the pattern recognition software can learn and translate into computer text from languages which are not made up of a small or limited set of alphanumeric characters (e.g., Japanese, Korean, and Chinese), it has particular utility for word processing and telecommunications in these languages.
In the practice of this invention, it is particularly desirable to use a single computer screen to display any initial forms, Font Symbols or other displays to be edited, and to create a nearby "window" of blank space where Handwritten Symbols are to be written, displayed and identified, and where the Font Symbols corresponding to the Handwritten Symbols are to be displayed. In this way, the user can view the text being edited and the proposed insert or change without significant movement (if any3 of the head and eyes. This is illustrated in Figs. 1 lA to 1 lD. This ~eature of the invention (proximity on one screen of text to be edited and the window into which new text is to be handwritten) is very important to the simple, rapid, comfortable use of the invention.

-~0-~3a~2572 In a preferred embodiment of this invention, the system "learns" the handwriting of a particular user prior to actual use. For example, if using the Roman alphabet, the twenty-six letters of the alphabet the numerals from 0 to 9 would be inserted into the database. Punctuation symbols, such as periods, commas, question marks, colons, semi-colons, hyphens and the like could also be inserted. There is virtually no limit to the Handwritten Symbols which can be recognized and stored in the database. Of course, the computer will have to store a suitable array of Font Symbols for conversion of the Handwritten Symbols. Different sets of Font Symbols could be created and stored in the permanent memory of the computer, as in ROM chip 54. For example, in English language usage, a chip could contain one (or more) fonts of numbers and letters, suitable punctuation symbols and appropriate mathematical symbols. Other chips could have stored Font Symbols for the Arabic9 Cyrillic or ~reek alphabets, Japanese, Chinese or Korean "Konji", symbols for use by architects or engineers, or chemical symbols (~, benzene rings and the like).
In Fig. 10, one of a series of learning screens is displayed and the user is prompted to write the numbers 0 through 4. The computer will attempt to match the written numbers with the existing database (if any). If it cannot be matched because there is no existing database or because there is a poor match with an existing database, the character is added to the database. This learning process continues ~mtil all of the alphanumeric (or other) characters and symbols to be ~L3(~2S~

used are entered into the database. The system has the capa-~ility of storing multiple Stroke characterization databases for systems used by more than one user. The existence of a unique Stroke characterization database for each user has the further advanage of making the writing angle irrelevant. As a result, the invention is adaptable to all handwriting styles and is usable by right-handed and left-handed persons. One feature may desirably be incorporated into the apparatus of the invention to accommodate left-handed and right-handed persons.
This feature is a receptacle (not shown) for the stylus connector on either side of housing 12, so that the stylus 16 may be connected on the left sic`e for left-handed persons and on the right side for right-handed persons.
Fig. 10 also provides an example of the use of "Softkeys". In addition to the input line, a variety of Softkeys appear. Each Softkey corresponds to a function that can be performed by the system. In order to execute the funtion, the user merely touches the indicated Point with the pen. The Softkey will then appear in reverse video and the selected function is performed. There are numerous advantages to Softkeys over traditional function keys. Some of the more significant of these are that the user is no longer reguired to memorize what function key performs what function; the need for keyboard overlays is eliminated: and different Softkeys can be made available (displayed and made operational) at diferent Points within a program.
Figures llA to llI demonstrates some of the simpli-fications in word processing made possible through the use of this invention. In Fig. llA a standard screen of text is displayed. The user of the keyboardless entry system decides that additional information needs to be added and draws an ~ ~.3~ 72 insert symbol (e.g., caret) on the screen at the desired position. A data entry "window" then appears. (Fig. llB).
The text is written in as Handwritten Symbols (Fig. llC), matched (converted to Font Symbols) ~Fig. ~;D), and then inserted (Fig. 11~). The operator reconsiders the addition and draws a horizontal line through the new material. (Fig. llF).
It is immediately erased. (Fig. llG). Next, the operator decides that a larger right-hand margin would be more appropriate for the text. A vertlcal line is drawn on the screen (Fig. llH) and the margin is automatically adjusted (Fig. llI).
A generalized block diagram of the editing process is provided in Fig. 13 and a description of that figure appears hereinbelow.
Figures 12A-12G illustrate how a blank form may be used for a hospital patient. The user of the system first calls up the proper blank form (Eig. 12A). This may be done, for example, by touching an appropriate Softkey. The area where the information, in this case a pulse observation, is to be inserted is touched with the pen (Fig. 12B). After the desired location is highlighted, a "window" appears directly below the space where the observation is to be recorded (Fig.
12C). The nurse then touches the pen on the match box which appears highlighted (Fig. 12D). The software then matches the handwritten input to the corresponding Font Symbols and displayes the result (Fig. 12E). If there is an accurate match, the "insert" block is touched (Fig. 12F), and the new observation is added to the patient's records (Fig. 12G). This mechanism is clearly applicable to a wide variety of "blank forms" in which data is inserted into a form or corrected. For example, it could be used to correct or update financial information in a spreadsheet program. All such applications ~30~

are within the purview of this invention. Vther information can be recorded in the sarne manner.
The reason for using a black background and white letters for the newly entered Font Symbols is to facilitate checking the accuracy of the inputted character.
Although this is preferable, it is not essential and a white background and black letters is also acceptable.
The ability to create a window and input data on the same screen and in physical proximity to the text being edited or space for data to be input is an irnportant feature of this invention, for it perrnits ease and speed in the use of the invention. The user's eye may focus on the space where the data will be inserted and the ability to contemporaneously display Handwritten Symbols and the corresponding Font Symbols makes it easy to see errors, when the system "misreads" a Handwritten Symbol, and then correct errors quickly and easily.
Referring first to Fig. 5, the overall operation and functioning of the pattern recognition software will now be described. When the operating system calls the pattern recognition program, the program begins in terminal 75 where a number of variables and counters are initialized. The software then proceeds to decision diamond 76 where the program determines if stylus 16 (Fig. 2) is in contact with input screen 18 (Fig. 2A~. The system provides a "pen down" s;gnal, as shown in processing box 78, as well as the X,Y coordinate voltages as locating signals, as described above.
Microcomputer 14 (Fig. 4), using the software according to the present invention, converts the X,Y coordinate locating signals into Stroke characteris~ics using programs stored in ROM 54 (Fig. 4), or a separate microcomputer can do the conversion, such as microcontoller 44. If a pen down signal is received, the software proceeds to processing box 80 where the individual locating signals are cornbined into "Strokes", a Strok being ~.~

~:~10;~S72 defined as the Point locating signals produced between a "pen down" signal and a "pen up" signal.
The system then calculates a transform, as described below, for each Point, transforming the Point coordinates from the X,Y cartesian coordinate system to a relational coordinate system. The software next proceeds to processing b~x 82, where it compares the Stroke with previously entered Strokes accumulated into a database, and determines if the Stroke is represented by a symbol in the database. If a match Is found (if the Font Symbol represented by the Strokes is recognized), as indicated in decision diamond 84, microprocessor 50 (Fig. 4) causes the symbol to be sent to display screen 20 (Fig. 4) as indicated in processing box 86. If a match is not found, microprocessor 50 (Fig. 4) causes a message to be displayed, as indicated in processing box 88, which requests further input from stylus on input screen 18 (Fig. 4) by either flashing an entry which is close to a match or a non-recognition symbol.
As mentioned above, the software compares the Stroke characteristics of each Handwritten Symbol to data entries previously stored in a database. In a preferred embodiment, the database is arranged into sections of characters or symbols by the number of Strokes needed to make the character or symbol. Within each section, the entries are randomly arranged at first, but after use, as explained herein, the most frequently used entries "rise" to the top of the database. It should be noted that each user will have his or her own particular style of writing a Handwritten Symbol and that each Handwritten Symbol may have a number of different variations.
For example, many people write the lower case letter "h" using a single Stroke. They do this by starting the pen on the writing tablet at a Point where they wish to place the top of the letter, drawing a vertical line downwardly to the base line, then 25i72 without removing the pen from the paper, proceeding back up to the midPoint of the previously drawn vertical line, over to the right and down to the base line when the pen is picked up from the paper. On the other hand, these sample people may draw the upper case letter "H" using two Strokes. They do this by drawing the left hand vertical line and horizontal line as is done for the lower case "H", picking the pen up from the tablet, and then drawing the right hand vertical line. Appendix I displays the data of the Stroke data Points for these two letters as the data is stored in memory after having been generated by an embodiment of the present invention.
As shown in Appendix I, the letter "h" as drawn at one particular time by one user has one Stroke (ns = 1) with 20 Points (np = 20) and x and y coordinate characteristics for the minimum, mean and maximum normalized values (l/80th of a line width) as follows: -17 and -6; 0 and 18; and 19 and 60, respectively. The values in the first vertical column are the Point-to-Point slopes, normalized to 360/256. The values in the second vertical column are the Point-to-Point average vertical positions above the base line, normalized to 1/80 of the line width. A typical line width is about 0.4 inches.
Referring now to Fig. 6, a software hierarchy of programs is depicted. At the top, overseeing the entire operation of computer system 10 ~Fig. 1), is an operating system as indicated by box 90. Applications programs shown in boxes 92 and 94, residing in RAM 56 (Fig. 4) and ROM 54 (Fig. 4) can be executed by microprocessor 50 (Fig. 4) under control of the operating systems. When a Handwritten Character is required or is indicated by an interrupt, handwriting recognition software 96 is called. A
first subroutine, indicated in box 98, encodes the X,Y coordinates into Strokes. The characteristics of the Strokes are then defined by a subroutine 100 followed by ~3~;~

comparison of the Strokes with a database that has been loaded from ROM 54 (Fig. 4)into RAM 56 (Fug. 4). The comparison is made by a subroutine 102. When the operating system is in the "learning" mode, the database is updated with the new Stroke data and symbols, as indicated in box 104. Similarly, a previously stored document can be edited by applications program 92 by using edit function 94 as called by the operator, who provides the instnlctions as input using the subroutines 98, 100 and 102 of handwriting recognition program 92.
Referring now also to Fig. 7, operating system 90 (Fig. 6) executes the Handwritten Character recognition software 96 (Fig. 6) by accepting as input the X,Y
coordinate Points, depicted in box 110, of the position of stylus 16 (Fig. 2) on input screen 18 (Fig. 2) and encodes these Points into Strokes as depicted in box 112. The program then characterizes the Strokes by some description set, such as considering the length, curvature, slope, and pOSitiOll of the Stroke, as depicted in box 114. In box 116 the best comparison is then found of the characterized Stroke or sequence of Strokes with those in the database. If a sufficiently close match is found, the character is identified in box 118 and the database entry is swapped with the entr~ above it as shown in box 120.
In this way, the most frequently identified characters will "rise" to the top of the database and the overall system performance, as measured in time to find a match, will be increased. If a match is not found, the user can add to the bottom of the database, as indicated in box 122.
With reference now to Figs. 8 and 9~ a flowchart of the computer program to recognize a particular Stroke sequence is set forth. The computer program begins in terminal 150 and proceeds to process the X,Y voltages from processing box 152, the voltages ha~ing been converted to a digital slgnal. The program then proceeds to decision box 154 where the program determines whether the pen or s~ylus 16 (Fig. 2) is out of contact with input screen 18. This determination is made by both the X voltage and the Y voltage being zero. If the program determines that the pen is up, then the Stroke is determined as having been completed and the program branches to decision box 156. In decision box 156, the program determines whether there are less than three Point in the Stroke and if so the program branches to decision box 158. In decision box 158, the program determines whether there are zero Points in the Stroke. If there are zero Points in the Stroke, then the program loops back to the beginning of processing box 152 where another set of Points is read. If the Point counter (incre-mented in processing box 164) indicates that there are more than zero Points, the program branches to processing box 172.
In processing box 172 the Stroke is identified as a dot and i~s height above the base line (HABL) is calculated in processing box 173. From processing box 173 the program proceeds to processing box 171.
However, if the pen down signal is received, the pro-gram branches to processing box 160 where the voltages are scaled to determine the coordinate Point using the following formulas:

X = alvl + bl Y = a2v2 ~ b2.

The constants a1 and bl are scaling parameters that are deter-mined from calibrating the input surface of the particular dis-play ~3~2~2 Once the voltages are scaled, the program proceeds to decision diamond 162 where the program determines whether it is an erroneous Point. This is done by comparing the distance between Points and eliminating a Point if the distance is to great (greater than .10 inches is presently used.) On the other hand, a Point is also eliminated if the Points are too close together. Points are presently thlnned out if they are within .015 inches.
The comparison problem that exists for the first Point is resolved by determining if a Point is the first Point after a pen is down and then that Point is used only to check the next Point which is accepted, assuming that that Point is within the maximum distance ( 10 inches).
If the distance between Points is determined as being outside the two criteria, the program drops the Point and branches back to the top of processing box 152 to read another pair of coordinate Point voltages.
On the other hand, if the Points fall within the cri-teria, the program continues to processing box 164 where a Point counter is incremented to keep track of the number of Points. This number is used in decision diamond 156, as mentioned hereinabove. The program then continues to processing box 166 where the Points are smoothed according to any one of a number of formulas. Smoothing is used to minimize noise from digitization, from erratic hand motion and from electronic noise. The simplest smoothing techni~ue is a multiple Point average which results in calculating new Points (xj'yj') as follows:

~:31~7~

Xj~ = ~ xj/(n2 - nl + 1) i=nl And similarly for Yj, smoothed over Points n, - n2.
Another simple method is called the running weighted aveMge method and utilizes the following formula:

Xj' = Ix Xj + ~ ) Xj, - 1 Alpha ;s a weighting constant that is usually positive (and less than one) and has been used at 0.25. The summations have been taken with n2 minus nl equal to one. A third method involves what is called a spline fit wherein the following formula is used:

Xj' = (xj l + 4 Xj + x~

Any of the foregoing methods can be applied either before or after filtering. The filtering is done so as to reduce the number of input Points and to space data so that difference and/or angle calculations can be made within acceptable random error bounds. A simple process of thinning a sequence of Points by excluding the acceptance of subsequent Points within a set distance of the previously accepted Points has been found to be an effective filter.
From processing box 166, the program proceeds to processing box 16~
where the Point is stored in an array that is incremented for each new Point since the last pen down signal. Thus, an addressable array of Points is created for each sequence of Points obtained ~rom a pen down to a pen up signal. This sequence of Points is called a ~3~2~

Strolce. From processing box 168, the program loops back to the top of processing box 152 where another Point is obtained until a pen up signal ends the Stroke.
In decision diamond 156, a determination was made as to whether there were less than three Points in a Stroke. By definition, if there are three or more Points in a Stroke, the Stroke is a line and not a dot. If there are three or more Points in the Stroke, the program branches to subroutine box 170. In subroutine box 170, discussed in greater detail hereinbelow with respect to Fig. 9, the Stroke is characterized as to its slope and base line height.
As can be seen from the foregoing, the segmentation of the steam of coordinate Points into a Stroke is based primarily on the determining when stylus 16 is "up" or not in contact with the surface of input screen 18. Alternatively, a stream of Points can be segmented to form Strokes on the basis of other considerations. For example they can be segmented based upon changes in a locally calculated curvature or upon a large local curvature. Local curvature is calculated by the change in distance along the input coordinates divided into the change in slope. This produces radius of curvature. When the radius of curvature changes rapidly with respect to distance along the input coordinates, or if the radius is too small, then a segmentation Stroke is assumed to end, and a new Stroke begun. Further segmentation techniques can look at the relative maximum and minimum in one or both coordinates and/or the curve crossings in the coordinates. However, these latter two methods have been determined to be less effective.
Characterizing a Stroke reduces the seqllence of coordinates defining the Stroke or segment to a set of characteristics that are unique, generalized and minimal. Unique-~æs7z ness refers to both factors that the same characteristics are generated by the same coordinates and that the characteristics are sufficient to regenerate an approximation to the original coordinate sequence. The term "generalized" is used to mean that the characterization is invariant under such transformations so that the symbols are invariant (e.g., translation and scaling or stretching or small tilt). The scaling of all distances is accomplished by taking a ratio of the distance to a writing entry line width.
The minimal set of segment characteristics have the follo~ing features:
(1) Stroke position: one or more of centroid/average, extent extreme or beginning and ending Points determined relative to the writing entry line, to previous Strokes, or to character extent or center;
(2) Stroke shape is characterized by one or more of average slope, change in slope (which is a measure of average curvature) and/or a change in curvature, by sequence of slopes over specific length segments or over fractional lengths, or by a gross description of linear direction or circular completion and opening direction;

(3) knd Stroke length as characterized by distance along the curve and/or the extent extremum along the coordinate system.
In one embodiment of the present invention, position-ing by centroid, extent extremum, and starting and ending coordinates have been successfully used. The Stroke shape is encoded as a sequence of slopes and vertical positions (relative to Stroke centroid). The Stroke length can be approximated by the number of filtered Points. Alternatively, ~IL3~ 72 the average curvature can be encoded in total slope change (along with length), change in starting to ending slope or fitting the slope angle versus length curve for rate of change of slope angle.
Additional characteristics that could be used include location of coordinate relative extrema, curve crossing, cusps, and Stroke direction. A particular method used to determine the unique characteristics is set forth below.
1. The numerical values of the Criteria for each Stroke of the Handwritten Symbol are determined.
2. The database values for each stroke of the previously learned Handwritten Symbol is determined and subtracted from the newly determined values respectively.
3. The absolute values of each difference are scaled, to make each of the five measurements reasonably equivalent to the others such as lengths scaled to height between lines.

4. The five thus-determined values are added.

5. A predetermined threshold is used as "goodness" test of recognition -- too high a value and Font Symbols are infrequently recognized and too low a value causes ~ont Symbols to be misidentified. Thresholds of approximately 1,000 are used initially and then switched to approximately 100 for improved recognition. If the threshold is exceeded, the comparison is discarded and an error message is created and displayed.

6. The database is searched to find a numerical minimum difference. If the minimum difference is below the acceptable threshold for recognition, the corresponding ~ont Symbol is displayed on the screen or the command is performed, as the case may be.

~31~7~

It has also been found that the preferred classification of a Stroke is a continuous one, rather than one that is grossly discrete. For example, determining a slope by angle in 256 directions rather than in 8 is desirable. Other non-continuous classifications can include bars/arches/hooks, number and closure of cusps or horizontal or vertical Strokes.
From subroutine 170, the program proceeds to processing box 171 where both an individual Stroke and one or more preceding Strokes are compared with a database entry that is stored in RAM 56 (Fig. 4).
This comparison initially begins with three eliminating questions that are asked by the program in decision diamonds 174, 176, and 178. In each case, if the database entry is eliminated, the program proceeds to a processing box 180 where the address of the next data entry is received and from which the program loops back to the top of processing box 171. In decision diamond 174, the first eliminator is asked by seeking if the number of Strokes are different. If the number of Strokes are the same, the program proceeds to decision diamond 176 where the average Height Above Base Line (HABL) is calculated and compared with the HABL of the data entry.
The entry is eliminated if the difference in the average HABL's is greater than one-half the height of the entry line. From a negative determination in decision diamond 176, the program proceeds to decision diamond 178 where the number of Points per Stroke are compared and the database entry is eliminated if the difference in number of Points is greater than ten. This determination varies from that made in decision diamond 174 because it is concerned only with the mlmber of Points for each Stroke. However, in decision diamond 174, certain letters, such as the capital letters "E" and "A", have more than one Strvke per letter.

~3~2~2 If a data entry is not eliminated by decision diamond 178, then the program proceeds to processing box 182 where the program calculates a gauge to be used to determine the closeness of the match between the selected entry in the database and the drawn Stroke. A
presently preferred gauge is the sum of the absolute values of the differences between the Stroke values and the database entry values of:
a) distances or lengths in units of l/80th of the line height (e.g., space 26, Fig.
2); and b) the slopes in units of l/256th of 360 over all the Points along the diagonal of the comparison matrix.
Alternatively, Dynamic Programming Techniques can be used to optimize the comparison using off-diagonal elements as well.
From processing box 182, the program proceeds to decision diamond 186 where a match is determined. In actuality, a match is determined by (the application of an arbitrary~ gauge (maximum allowable variance), which is the sum of absolute values of the differences between the entered Stroke characterization and that of the stored database entry. In processing box 183, the lower of the present gauge and the previous lower gauge is saved as the best match. The program then goes to decision diamond 184 where a determination is made whether the present entry is the last database entry. If it is not, the program branches to processing box 180 where the next entry is selected. If it is the last entry, the program proceeds to decision diamond 185 where a determination of a match is made on the basis of the gauge being below a plredetermined threshold. This threshold is set by the user based on experience with the system.
If no match is obtained, the program branches to decision diamond 188 where a determination is made whether all Strokes have been checked. If the last Stroke has beeD

~572 checked, then the present Stroke is compared in sequence with a previous Stroke to all two Stroke entries. As in the comparison with all one Stroke dictionary entries, the best fit comparison for all entered Strokes is the recognized symbol or sequence of symbols.
However, if the last Stroke has been read and there still is not a match, then the program proceeds to processing box 190 where a question is displayed on display screen 20 asking the user if a new Font Symbol should be added to the database. The user responds and that response is used in decision diamond 192. Either the Stroke sequence is added to the database in processing box 194 and the program branches back to the top of processing box 152, or the program branches immediately to the top of processing box 152.
On the other hand, if a match is determined in decision diamond 1~6, the program branches to processing box 195 where the program shuffles the database by interchanging the serial location of the matched entry with the entry above it. The program then proceeds to processing box 196 where the program zeros the Point counter and the increment counter. The program next proceeds to processing box 198 where the matched and characterized Stroke OT
Strokes are displayed by the computer as the identified Font Symbol. This display is located at the position in which the entry was made on input screen 18 (Fig. 2).
From processing box 198, the program proceeds to processing box 200 where the program can act on any commands which it has interpreted. An alternative characte~ization of the Stroke uses the Points themselves rather than the length, scope, curvature and position.

1 ~302~'72 `~

With reference now to Fig. 9, this Stroke characteriza-tion is depicted in greater detail. Stroke characteri~ation subroutine 170 essentially performs a mathematical transforma-tion of each Point on a Point-by-Point basis to transform the Points from an X,~ Cartesian coordinate system to one in which the coordinates are the normalized slope of each Point and the normalized height of each Point dbove the base line (HABL).
Subroutine 170 first calculates the Point to Point slope in processing box 220 and then calculates the height of each Point above the base line in processing box 22~. The slope and HABL of each Point are then normalized respectively to 1/256th of 2 Pi and to 1/80th of the width of the entry line in processing box 224. From processing box 224, the system pro-ceeds to processing box 226 where the calculated normalized values for each Point are stored in an addressable array. The subroutine then returns to the program through terminal 228.
When the comparison is made between each Stroke and the stored values, the comparison is made by the normalized Point slope and Point height above base line. As mentioned above, a match is determined by an arbitrary gauge which is the sum of absolute values of the differences between the written Stroke and the stored or dictionary Stroke. The system learns by adding new Strokes to the dictionary database. Once the database fills up, those Font Symbols that are in~requently used are replaced by new entries.
In a working embodiment of the present invention, the algorithm successfully identified upper and lower case letters and numbers when written discretely from one another. For Handwritten Symbols that are written such that they are continuous, direct extrapolation would re~uire searching a database sequentially for one, two, three, etc. Stroke symbols ~ 72 and looking for the best fit. Upon identification of a Stroke fit, a "new" letter is tenatively recognized, except that the next few Strokes are analyzed to check if they change the previous symbol for a better fit. For example, two Strokes that have been identified as "ones" would be combined and changed to the capital letter "H~' once a cross bar was identified.
The system design demonstrated by Figs. 7 to 9 could easily be coded by one with ordinary skill in the art of computer programming into almost any computer language. The source code listings for one application program utilizing the disclosed invention is included as Appendix II. ~he software in Appendix II is written in Microsoft Basic, a common computer language available for virtually all microcomputers and operating systems. The program is a complete text editing demonstration, which takes advantage of many of the key features of this invention and shows the improvements that can be made upon traditional word processing systems through the utilization of this invention.
Program lines 2600 to 4000 contain the character recognition subroutine which includes the software code necessary to get X and Y coordinates. This section of the program corresponds to Fig. 8.
Program lines 2600 to 2699 make up a su~routine designed to obtain the X and Y coordinates of a given Point.
This code corresponds to boxes 152, 154, 160, 162, 164, 166 and 168 of Fig. 8.
Program lines 3000 to 3339 constitute a Point and Stroke analysis and characterization routine embodying boxes 156, 158, 170, 172 and 173 of Fig. 8.

Program lines 3700 to 3790 make up a subroutine designed to compare the analyzed Strok~s to a Stroke database.
These program lines embody boxes 171 to 184 of Fig. 8.
Program lines 3810 to 3980 make up a subroutine which is designed to learn a new character. This code embodies boxes 186, 188, 190, 192 and 194 of Fig. 8.
Program lines 3060 to 3273 make up a subroutine designed for Stroke characterization purposes. This section of the code corresponds to Fig. 9.
Program lines 3060 to 3095 are used to calculate Point-to-Point slopes and embody box 220.
Program lines 3058, 3241 and 3262 are used to calculate a height above baseline (HABL) and correspond to box 222 of Fig. 9.
Programs lines 3253, 3270-3273 are used to normalize the Point height and slope and correspond to box 224 of Fig. 9.
Program line 3253 is used to store the height above baseline and embodies box 226 of Fig. 9.
The foregoing program can be stored in the memory of a microcomputer of microprocessor with a requirement of approximately 25~ of machine memory, so that it can be seen that the use of the program does not use up a lot of expensive memory and is relatively fast in executing the program's operation. If the program is written in a language other than Basic, requiring less memory, such as assembly language, the size of the program can be made smaller.
Boxes 195 to 200 of Fig. 8 appear in logical places throughout the code.
A dictionary of the variables of the relevant code section is included as Appendix III.
With reference now to Fig. 13, a flowchart for the editing software ("Editor") demonstrated by Figs. llA to llI

2~

and described above is depicted. Once the Editor is loaded into the system (box 229), control of the screen is returned to the system. The system then proceeds in the normal manner described above to acquire Points and display them (box 230), convert the Points into Strokes (box 231), characterize each Stroke (box 232), and attempt to match the Stroke or Strokes with the database (box 233). In processing box ~34, the system sends each Handwritten Symbol to the Editor to interpret and execute a command if necessary. At decision diamond 235, the Editor determines whether the Handwritten Symbol is an Editing Symbol or a Font Symbol. If the character is determined to be an Editing Symbol, the Editor proceeds to processing box 236 where it determines which Editing Symbol has been entered and executes the Editing Function. If the character is determined not to be an Editing Symbol, then the alphanumeric character corresponding to the handwritten entry is displayed at pro-cessing box 237. In an alternate configuration of the Editor, Font Symbols will only be accepted when the Editor is in the "Insert Mode." This structure insures that each Font Symbol is verified before being added to a document.
The Editor uses a variety of symbols designed to make editing on the system similar to, but much more efficient than, traditional editing with pencil and paper. These functions include, but are not limited to:
DELETE symbol - " " A horizontal line drawn through a character or characters. The Editor will remove the underlying characters and reformat the text.
ADJUST MA~GINS symbol - "¦" A vertical line longer then the height of one line on the display. The Editor will adjust the margin to the indicated position and reformat the text.

~3~2~

INSERT symbol - "~" A caret drawn at the Point where text is to be added. The ~ditor displays an input writing line (Fi~. 118) and when input is recognized inserts it into the text.
MAR~ TEXT symbols - ""' and "~ A less than and greater than symbol drawn at the be~inning and end of a block of text. The marked text is displayed in reverse video and then special block functions can be performed.
DELETE MARKED TEXT - A delete symbol drawn within marked text will erase the marked text and reformat.
MOVE MAR~ED TEXT - An insert symbol drawn anywhere within the text moves the marked text to the indicated pOsitioll, deletes it from its origional position and reformats the text.
REPLACE MAR~ED TEXT - An insert symbol drawn within the marked text displays an input line and replaces the marked text with the inputted text.
The Editing Symbols described above can be changed to the particular Editin~ Symbols preferred by each user, thereby customizin~ the Editor and preventing new users from having to learn unfamiliar Editing Symbols.
Further modifications and enhancements to the present invention would be obvious to those skilled in the art. For example, the common characteristics of each Font Symbol could be extracted and organized into a synthetic symbol. The synthetic symbol's characteristics could then be exaggerated to maximize their variance from all other synthetic symbols. This would create a very compact, optimal database. On the other hand, as an example, a database created by the described preferred embodiment of the invention usually results in two to three different characterizations for each s~mbol.

The invention has numerous useful applications, almost without limitation. The most obvious applications are text editing and filling out and modifying forms. Some of the many other applications that may not come to mind as readily are writing in languages utili7ing large numbers of symbols like Japanese or Chinese; writing in Arabic and similar lan-guages made up of a limited number of complex symbols; writing chemical equations, including those involving organic compounds; writing music (a "window" with five parallel lines can be provided for musical applications); writing symbols and codes for graphic manipulation of data, including the transfer of graphic data to a spreadsheet; in education, as where predetermined questions are presented on the screens and the answers written in long-hand; as in teaching mathematics, as when numbers are manually inserted in equations and the equation analyzed to determine the result using those numbers;
in CAD/CAM applications involving symbols, geometric shapes and the like.
Although the invention has been described in terms of a selected preferred embodiment encompassing the apparatus and methods aspects of a keyboardless computer system, the invention should not be deemed limited thereto, since other embodiments and modifications will readily occur to one skilled in the art.

`- ~3~ 72 APPEND I ~ I

'h' (1) ns = 1 x = (-17.Ø.19) y = (-6..18..60) 1) np = 20 x = (-17.Ø.1g) y = (-6..18..60) 5, 42 -57, 34 -85, 26 -71, 19 -76, 10 -64, 3 -89, -3 -72, _9 - 85, - 17 -72, -24 47, -17 56, -11 43, - 3 39, 3 11, 7 _9, 5 - 57, - 3 -71, -11 - 71, - 18 'H' (1) ns = 2 x = (-27.Ø.37) y = ~-20..18..61) 1) np = 14 x = ( -27. . -12. . -2) y = ( -20. .22. .61) _9, 37 4, 38 -39, 32 -48, 25 -58, 16 -71, 8 -72, 2 -64, -4 -89, -11 -72, -17 80, -24 -89, -30 -80, -36 2) np - 20 x = (-21..10..37) y = (-15..16..59) 27, 43 -80, 37 -71, 29 -98, 23 -80, 16 -78, 8 -85, -89, -6 - 80, - 12 -30, -18 - 64, - 25 - 64, - 31 48, -25 56, - 18 48, 12 64, -6 89, -124, 0 - 124, -2 ~3~2~:
APPEND I X I I

l REM Z SERI~S COPYWRITE LINUS TECHNOLOGIES INCORPORATED~ RESTON~ VA., 7/30/85 10 DEFINT A-Y : REM all integer~ except z 20 DIM X( 2000 ) ,YI 2000 ) ,D( 9, 800 ) ,DN(300),DC( 300)~SX( 80 ) ,SY( 80 ) ,SL( 80 ) ,SC( 80 ) ,SA( 80) ,SXX( 80) ,SXN( 80),SYX( 80~SYNl 80) ,SNO(80) ,MTITL$(20) ,A$(1500),LL(24), AS$ ( 200),SLET( 80 ),DBC( 9, 1 0 ), ASTRT(80)~AEND(80) 25 PRINT FRE(O) 3 0 PRINT " Z SERIES COPYWRITE: LINUS TECHNOLOGIES INCORPORATED~ RESTON~ VA., 7/30 /85"
IMARGN=5 : IMARGX=62 : JTOP=l : JBTM=15 : JMENU=160 :CR$="~"
KYBD=0: LHT=16 : SXTT= 4: JTX= 0: ACPT=1000 60 LHT4=LHT\4 :LHT3=LHT\3 :LHT5=LHT\5 :LHT2=LHT\2 70 PRINT "PLEASE INPUT PEN SWITCH...-1 TO RERUN~ 0 TO RUN~ 1 TO RUN & STORE": INPUT SWTPN
IF SWTPN > ~1 THEN GOSUB 1 0700 :REM TOUCH TECH SCREEN IN ASCII @ 9600 80 PRINT rPLEASE INPUT DEBUG ...~5 TO 5 ": INPUT DBUG
85 PRINT ~PLEASE INPUT ACCEPTANCE CRITERIA...10 TO 1000 ": INPUT ACPT
90 PRINT "PLEASE INPUT EDIT/LEARN SWITCH...l TO EDIT": INPUT EDLN
92 PRINT "PLEASE INPUT KEYBOARD SWITCH...0 FOR KEYS, 1 FOR MENU n INPUT KYBD
95 PRINT ~PLEASE INPUT RESTART SWITCH...l TO RESTART WITH STORED DATA BASE": INPUT RESTRT
97 IFAVE=0 IF SWTPN=- l THEN IFAVE=0 RE~ PRINT "PLEASE INPUT AVERAGING SWITCH . .
. 1 TO READ & AVERAGE~ 2 TO AVERAGE INPUT" INPUT IFAVE
100 KEY OFF SCREEN 2 : CLS
120 IF RESTRT = l THEN GOSUB 12700 130 IF EDLN = 1 THEN GOSUB 12100 : REM READ IN TEXT
140 IF EDLN = 1 THEN GOSUB 600 : REM PRINT TEXT
15 0 I F SWTPN = 1 THEN GOSUB 7200 151 I F SWTPN = ~1 THEN GOSUB 7000 1 7 0 I F EDLN <> l THEN GOSUB 6100 180 IF EDLN <> 1 THEN GOSUB 12500 205 LINY=0 2 1 0 I F SWTPN = ~1 THEN GOSUB 7100 ELSE GOSUB 2600 REM TOUCH TECH SCREEN I N ASC
II @ 9600 21 1 IF SWTPN =1 THEN GOSUB 7300 221 IF NP > 2000 THEN LOCATE 23~1 PRINT "TOO MANY POINTS": STOP
222 I F NP < 4 THEN GOTO 200 230 GOSUB 3000 : GOSUB 3400 :REM -~<>~ P~E
240 ON NCHAR GOTO 1200~1300~1700~6200~6700~6500~6600~12500~6900~200 :REM DELETE~MOVE~FORMAT~INSERT~WRITE OVER~REMOVE~PARAGRAPH~ INSERT CHARACTER, END

605 LOCATE 23~20: PRINT " "~
610 I=II : J-JJ : REM INITIAL DISPLAY POINT FOR NC1 620 FOR X=NC 1 TO NC
630 I F A$ ( K) <> CR$ THEN GOTO 660 640 LOCATE J,I: PRINT " " : I=I+1: IF I < 81 GOTO 640 650 J=J+ 1 : I = IMARGN : LL( J ) -K : GOTO 740 660 IF I< IMARGX THEN GOTO 670 ELSE IF A$1KJ=" " GOTO 690 670 IF J> JBTM THEN LOCATE 21~20 PRINT "READY", : RETURN
680 LOCATE J,I: IF I=IN THEN GOTO 710 ELSE PRINT A$(K) I=I+1: GOTO 740 690 LOCATE J, I : PRINT " " : I=I+1: IF I< 81 GOTO 690 7 0 0 J=J + 1: I = I MARGN : LL(J)=K+1 : GOTO 740 710 IF A$( K) <> " " THEN GOTO 730 720 IF LL(J)=K GOTO 740 730 I=I+1: PRINT A$(K) 740 I F I > IMARGX+10 THEN GOTO 690 ELSE NEXT K
7 50 I F J> JTX THEN GOTO 790 760 JS=J
765 LOCATE J,I: PRINT " ": I=I+1: IF I< 81 GOTO 765 770 J=J+1 : I=IMARGN: IF J > JTX THEN GOTO 780 ELSE GOTO 765 ~44~

~ ~3~2~i~2 ~

780 J=JS
790 JTX=J : LOCATE 23,20: PRINT "READY", :RETURN

12 a 5 XX=SXX(1): XN=SXN(1): YX=SYX(1): YN=SYN~l) 1206 IF NSTRK=1 GOTO 1220 1210 FOR L=2 TO NSTRK
1212 IF XX < SXX(L) THEN XX=SXX(L) 1214 IF XN > SXN(L) THEN XN=SXN(L) 1216 IF YX < SYX(L~ THEN YX=SYX(L) 1218 IF YN > SYN(L) THEN YN=SYNiL) 1220 IN=IMARGN
1225 I=INT(XX/8)+1 : IF I < IN THEN I=IN
1230 J=INT(YX/8)+1 : ML=LL(J) :M2=ML+I-IN : IF A$(ML)=" " THEN M2=M2~1 1231 IF A$(ML)=CR$ THEN M2=M2+1 1232 I=INT(XN/8)+1 : IF I < IN THEN I=IN
1234 J=INT(YN/8)+1 : ML=LL(Jl :Ml=ML+I-IN : IF A$(ML)=" " THEN Ml-Ml+l 1240 IF A$(ML)=CR$ THEN Ml=M1+1 1250 MD=M2-Ml+l: IF MD < 0 THEN MD=M1-M2+1 : Ml=M2 1260 FOR M=Ml TO NC : A$(M)=A$(M+MD) : IF M+MD-NC THEN GOTO 1270 ELSE NEXT M
1270 FOR M=NC-MD~l TO NC :A$(M)= " " : NEXT M
1280 II=I: JJ=J: NCl=Ml : GOSUB 600 1290 NC=NC-MD : GOTO 200 1305 IN=IMARGN
1310 XX=SXX(1): XN=SXN(1): YX=SYX(1): YN=SYN(1) 1320 XP=(XN+XX)/2: YP=(YN+YX)/2 :REM AVE BRACKET POSITION
1330 I=INT(XP/8)+1: J=INT(YP/8)+1:REM CONVERT X,Y TO I,J
1340 ML=LL(J): Ml=ML~I-IN :REM CALC A ARRAY INDEX OF LETTER AT I,J
1350 IF A$(ML)=" " THEN M1=Ml+l 1360 IF A$1ML)=CR$ THEN Ml=Ml+l 1390 XX=SXX(2): XN=SXN(2): YX=SYX(2): YN=SYN(2) 1400 XP=(XN+XX)/2: YP=(YN+YX)/2 :REM AVE BRACKET POSITION
1410 I=INT(XP/8)+1: J=INT(YP/8)~1:REM CONVERT X,Y TO I,J
1420 ML=LL(J): M2=ML+I-IN :REM CALC A ARRAY INDEX OF LETTER AT I,J
1430 IF A$(ML)=" " THEN M2=M2+1 1440 IF A$~ML)=CR$ THEN M2=M2+1 1450 M3=0:REM INITIATE COUNTER
1460 FOR M=Ml TO M2 :REM LOOP OVER PORTION CUT
1470 M3=M3+1: REM INCREMENT COUNTER
1480 AS$(M3)=A$(M) :NEXT M :REM COPY CUT TEXT
1490 XX-SXX~3): XN=SXN~3): YX=SYX13): YN=SYN(3) 1500 REM INSERT WITH M3 LETTERS STORED IN AS$ & xx,xn,yx,yn 1520 XP=IXN+XX)/2: YP=(YN+YX)/2 :REM AVE BRACKET POSITION
1530 I=INT~XP/8)+1: J=INT~YP/8)+1:REM CONVERT X,Y TO I,J
1540 ML=LL(J): M3=ML~I-IMARGN :REM CALC A ARRAY INDEX OF LETTER AT I ,J
1550 IF A$(ML)=" `' THEN M3=M3+1 15 60 IF A$1ML)=CR~ THEN M3=M3+1 1570 MD=M2-Ml+l : IF MD > O THEN GOTO 1580 ELSE GOTO 200 1580 FOR M=Ml TO NC : REM LOOP OVER A$ ARRAY POSITIONS TO BE SHIFTED
1590 A$~M)=A$1M+MD) : REM SHIFT A$ ARRAY LETTERS
1600 IF M+MD = NC THEN GOTO 1610 ELSE NEXT M : REM STOP AT END OF ARRAY=NC
1610 IF M3 > M2 THEN M3=M3-MD :REM OFF SET INSERTION POINT TO ACCOUNT FOR DELETION
1620 FOR M=NC-MD TO M3 STEP -1 : REM SPRED ARRAY 'l`O MAKE ROOM FOR INSERTION
1630 A$(M+.~D)=A$(M) :REM MOVE LETTERS

16 50 FOR M=l TO MD :REM LOOP OVER CHARACTERS
1660 A$(M3+M-l)=AS$(M) :REM INSERT LETTERS

1680 CLS: II=IMARGN: JJ=JTOP: NCl=l : GOSUB 600 ~ 72 ~

1720 XP=(SXN(L)+SXX(L))\2 :REM AVE BRACKET POSITION
1730 I=XP\8+1 :REM CONVERT X TO I
1740 IF ABS(I-IMARGN) <ABS(I-IMARGX) THEN IMARGN=I ELSE IMARGX=I
1750 CLS: II=IMARGN: JJ=JTOP: NCl=1 : GOSUB 600 2600 REM TT ACQUIRE POINTS IN ASCII @ 9600 WITH TIME 0[1T
2603 M=20 2605 IF LOC(2) > 0 THEN IPUT$=INPUT$(1,2) : GOTO 2605 2606 PRINT #2,"G" :N=0 2610 IF LOC(2) < 40 THEN GOTO 2610 2620 NU=0: INPUT #2,XP,YP :INPUT #2,XP,YP :INPUT #2,XPA,YPA :INPUT #2,XP0,YPo 2630 N=N+l: XPA=(XPA+XP0)\2: YPA=(YPA+YP0)\2: XP0=XPA: YP0=YPA: X(N~=XPA: Y(N)=YPA
2640 INPUT #2,XP,YP
2653 XPA=(XP+3*XPA)\4: YPA=(YP+3*YPA)\4 2657 IF ABS(XPA-XP0)+ABS(YPA-YP0) < 3 THEN GOTO 2672 2660 I=32*XPA\AX+BX:J=32*YPA\AY+BY:PSET(I,J) 2670 N=N+l : X(N)=XPA :Y(N)=YPA: XP0=XPA: YP0=YPA
2672 IF LOC(2) > 9 THEN GOTO 2640 2675 MM=0 2680 MM-MM+l: IF LOC(2) > 9 THEN GOTO 2640 ELSE IF MM < M THEN GOTQ 2680 2685 X(N)=-X(N): IF X(N) = 0 THEN X(N)=-l 2690 IF LOC(2) > 39 THEN GOTO 2620 ELSE NU=NU+l :IF NU < 4000 THEN GOTO 2690 2695 PRINT #2,"S": NP=N
2696 IF DEBUG <> 0 THEN LOCATE 20,2 :PRINT "NP=",NP
2697 IF IFAVE=2 THEN GOSUB 4200 2698 IF DEBUG <~ 0 THEN LOCATE 20,12 :PRINT NP

3005 REM GOSUB 4200 :REM 2 POINT AVERAGE POINTS
3010 Al=0: A2=0: DA1=0: DA2=0: SEND=0: ZX=0: ZY=0: ZA=0: ZDA=0: ZL=0: NSP=0 3015 NSTRK=0: XX=ABS(X(l)): XN=XX: YX=Y(1): YN=YX: Ml=1: M2=1: M3=2: NLONG-0 3020 FOR M=2 TO NP
3025 IF X(M) < 0 THEN SEND=2 :X(M)=-X(M) 3030 IF M > M1 GOTO 3035 ELSE 3391 3035 IF X(M1) < 0 THEN M1=M: GOTO 3391 3040 DX=X(M)-X(M1): DY=Y~M)-Y(Ml): ADX=ABS(DX): ADY=ABS(DY): DS=AD~+ADY
3043 IF AY > 0 THEN DY=-DY
3044 IF DS < 3 THEN GOTO 3391 3052 IF X(M) < XN THEN XN=X(M) 3053 IF X(M) > XX THEN XX=X(M) 3054 IF Y(M) < YN THEN YN=Y(M) 3056 IF Y(M) > YX THEN YX=Y(M) 3058 ZX=ZX+X(M)~DS: ZY=Z~+Y(M)*DS: Z.L=ZL+DS: NSP=NSP+l 3060 IF ADX < ADY THEN GOTO 3080 :REM ENCODE ANGLE 0-255 +-n256 3070 IF DX > 0 THEN Al=64-(32*DY)\DX ELSE Al=192-(32*DY)\DX

3080 IF DY > 0 THEN A1= (32*DX)\DY ELSE A1=12~+(32*DX)\DY
3085 IF NSP>M2 THEN GOTO 3090 3086 IF A1<0 THEN Al=A1+256 3087 ZA=ZA+A1*DS

3090 IF Al-A2 < -127 THEN Al=Al+256 : GOTO 3090 3095 IF A1-A2 > 128 THEN Al=Al-256 : GOTO 3095 3100 ZA=ZA+A1*DS
3110 DA1=Al-A2 3115 ZDA=ZDA+DA1 3120 IF NSP > M3 THEN ADA=(DA2+ADA)/2 ELSE ADA-DA1 : ASTRTINSTRK+1)=(Al+A2)\2 3130 IF NSP = M3+1 THEN ASTRT(NSTRK+l)=(Al+A2)\2 3140 IF ABS(DAl-ADA) > 80 THEN SEND=1 3150 IF ABS(DA1) > 64 THEN SEND=l 3190 IF SEND=0 THEN GOTO 3300 &~ ~3~32~

3205 IF SEND = l THEN GOTO 3220 3206 X(M)=-X(M) 3208 SEND=0: SZL=ZL: SZL=32*SZL\AY: IF SZL < 0 THEN SZL=-SZL
3209 IF NSP < 3 THEN GOTO 3210 ELSE IF SZL > 2 THEN Ml=M+l: GOTO 3250 3210 IF NSTRK > 0 THEN IF X(SNO(NSTRK)) > 0 THEN X(SNO(NSTRK))=-X(SNO(NSTRK)) 3212 Ml=M+l 3220 SEND=0: SZL=ZL-DS: SZL=32*SZL\AY: IF SZL < 0 THEN SZL=-SZL
3226 IF NSP < 4 THEN GOTO 3300 ELSE IF SZL < LHT5 THEN GOTO 3300 3230 Ml=M
3240 ZX=ZX-X(M)*DS
3241 ZY=ZY-Y(M)*DS
3242 ZL=ZL-DS: ZA=ZA-Al*DS: ZDA=ZDA-DAl 3243 NSP=NSP-1 3250 NSTRK=NSTRK+l 3253 SL(NSTRK)=50*SZL\LHT: AEND(NSTRK)=(A3~A4)\2: SC(NSTRK)=ZDA : AZA=ZA/ZL
3254 IF AZA > 255 THEN AZA=AZA-256 : GOTO 3254 :REM USE 128 HERE FOR DIRECTION INDEPENDENCE
3256 IF AZA < 0 THEN AZA=AZA+256 : GOTO 3256 3260 SX(NSTRK)=ZX/ZL: SX(NSTRK)=32~SX~NSTRK)\AX+BX
3262 SY(NSTRK)=ZY/ZL: SY(NSTRK)=32*SY(NSTRK)\AY~BY
3264 SA(NSTRK)=AZA
3270 SXX(NSTRK)=32*XX\AX~BX: SXN(NSTRK)=32*XN\AX~BX: SNO(NSTRK)=M
3272 IF AY < O THEN SYN(NSTRK)=32~YX\AY+BY: SYX(NSTRK)=32*YN\AY+BY : GOTO 3280 3273 SYX(NSTRK)=32*YX\AY+BY: SYN(NSTRK)=32*YN\AY~BY
3280 IF DBUG > 3 THEN LPRINT USING " ##";M,NSP,X(M),Y(M),ZL,ZA,Al,DAl,ADA,ZDA,(Al+A2+A3-~A4)\4 ELSE IF DBUG < -3 THEN PRINT USING " ##";M,NSP,X(M),Y(M),ZL, ZA,Al,DA1,ADA,ZDA,(A1+A2~A3~A4)\4 3281 IF DBUG > 2 THEN LPRINT "SL,SA,SC,AS,AE",SL(NSTRK) SA(NSTRK) SC(NSTRK) ASTRTINSTRK) AEND(NSTRK) ELSE IF DBUG < -2 THEN PRINT "SL,SA,SC,AS,AE",SL(NSTRK) SAINSTRK) SC(NSTRK) ASTRT(NSTRK) AENDlNSTRK) 3285 A1=0; A2=0: DA1=0: DA2=0:DS2=0:DS1=0:SEND=0: ZX=0: ZY=0: ZA=0: ZDA=0: ZL=0 3290 XX=ABS(X(Ml)): XN=XX :YX=Y(~1): YN=YX: NLONG=0 :NSP=0 3310 M1=M
3320 DA3=DA2: DA2=DA1: DS2=DSl: DSl=DS: A4=A3: A3=A2: A2=A1 3390 IF DBUG > 3 THEN LPRINT USING " #~";M,NSP,X(M),Y(M),7L,ZA,A1,DA1,A~A,ZDA,(A1+A2~A3+A4)\4 ELSE IF DBUG < -3 THEN PRINT USING " #~";M,NSP,X(M),Y(M),ZL,ZA,A1,DA1,ADA,ZDA,(A1+A2~A3+A4)\4 3392 IF DBUG > 1 THEN LPRINT " I NO X Y L A C XX XN Y
X YN ST ND"
3393 IF DBUG < -1 THEN LOCATE 9,1 :PRINT " I NO X Y L A C
XX XN YX YN ST ND"
3394 IF DBUG < -1 THEN LOCATE 10,1 :FOR I=1 TO NSTRK:PRINT USING ~#~###"iI,SNO(I),SX(I),SY(I),SL(I),SA(I),SC(I).SXX(I),SXN(I).SYX(I),SYN(I),ASTRT(I),AEND(I) :NEXT I
3395 IF DBUG > 1 THEN FOR I=1 TO NSTRK: LPRINT USING ~ #"iI,SNO(I),SX(I),SY(I),SL(I),SA(I),SC(I),SXX(I),SXN(I),SYX(I),SYN(I),ASTRT(I),AEND(I) :NEXT I
3396 IF NSTRK > 1 THEN GOSUB 4000 ELSE GOTO 3399 3397 IF DBUG < -1 THEN FOR I=l TO NSTRK:PRINT USING n ~ # # # # ~; I,SNO(I),SX(I),SY(I) ,SL(I),SA~I),SC(I),SXX(I),SXN(I),SYX(I),SYN(I),ASTRT(I),AEND(I) :NEXT I
3398 IF DBUG > l THEN FOR I=l TO NSTRK: LPRINT USING ~#~##n;IISNO(I),SX(I),SY( I),SL(I),SA(I),SC(I),SXX(I),SXN(I),SYX(I),SYN(I),ASTRT(I),AEND(I) :NEXT I

3410 FOR L=l TO NSTRK
3412 A1=(SA(L)~32)\64: IF A1 > 3 THEN Al=0 3416 IF Al = O THEN IF SL(L) > 100 THEN NCHAR=3: RETURN: REM VERTICAL
3418 IF Al = 1 THEN IF SL(L) > 60 THEN NCHAR=l: RETURN: REM HORIZONTAL
3420 IF Al = 2 THEN IF SL(L) > 100 THEN NCHAR=3: RETURN: REM VERTICAL
3422 IF Al = 3 THEN IF SL(L) > 60 THEN NCHAR=l: RETURN: RFM HORIZONTAL

3510 ED=l :GOSUB 3600 :ED =0 3515 IF NLET > 0 THEN GOTO 3530 3520 NCHAR=10: LOCATE 20,1: PRINT "TRY AGAIN" :RETURN
3530 IF CS$ = "-" THEN NCHAR =l :RETURN
3532 IF NLET = 3 THEN IF CS$ = " " THEN NCHAR=2 :RETURN
3536 IF CS$ = "^" THEN NCHAR=4 :RETURN
3538 IF CS$ = "\" THEN NCHAR=g :RETURN
3540 IF CS$ = "P" THEN NCHAR=7 :RETURN
3542 IF CS$ = "E" THEN NCHAR=8 :RETURN
3544 IF CS$ = "/" THEN NCHAR=6 :RETURN
3546 IF NLET= 1 THEN NCHAR=5 :RETURN

3602 IF DBUG > 4 THEN LPRINT USING " ##"; SXX(l),SXN(1),SYX(l),SYN(1),LHT4 3603 SLET(1)=1: NLET=l: IF NSTRK=l THEN GOTO 3650 3605 FOR L=2 TO NSTRK
3606 IF DBUG > 4 THEN LPRINT USING " ##"; SXX(L),SXN(L),SYX(L),SYN(L) 3607 ICONT=0 3610 FOR Ll=1 TO 2 : IF L > 2 THEN GOTO 3615 ELSE IF L1=2 GOTO 3635 3615 IF SXX(L-Ll~ > SXX(L) THEN GOTO 3630 ELSE IF (SXX(L-Ll)+LHT4) ~ SXN(L) THEN GOTO 3635 3620 IF ABS((SYX(L)+SYN(L))-(SYX(L-L1)+SYN(L-Ll))) > LHT THEN GOTO 3635 3629 ICONT=L1 :GOTO 3635 3630 IF SXN(L-L1) > SXX(L)~LHT4 THEN GOTO 3635 ELSE GOTO 3620 3635 NEXT Ll 3640 IF ICONT=0 THEN NLET=NLET+l :SLET(L)=NLET: GOTO 3649 3645 NLET=SLET(L-ICONT) : SLET(L)=NLET :SLET(L-l)=NLET
3646 IF DBUG > 3 THEN LPRINT "L,NLET,SLET",L,NLET,SLET(L-1),SLET(L-2) 3652 IF ED=1 THEN ZLINY=0: FOR LMN--1 TO NSTRK : ZLINY=ZLINY+SYX(LMN)+SYN(LMN): N
EXT LMN : LINY=ZLINY/NSTRK :LINY=(l+LINY\16)*8+4 :IF DBUG > O THEN LPRINT "LINY=",LINY ELSE IF DBUG < 0 THEN LOCATE 22,1 :PRINT "LINY=",LINY
3655 MCHR=l: NST=0: XX=-l: XN=1000: XXl=-100 :YX=-1 :YN=1000 :YX1=-100 3656 FOR LSTRK=1 TO NSTRK+1 3657 LST=LSTRK :IF LSTRK = NSTRK+l THEN GOTO 3659 3658 IF SLET(LSTRK) = MCHR THEN NST=NST+1: GOTO 3-690 3659 IF NST > 10 THEN LOCATE 23,1 : PRINT "TOO MANY STROKES", :STOP
3660 FOR M=l TO NST :LMN=LST-NST+M-1 3661 DBC(1,M)=SL(LMN): DBC(2,M)=SA(LMN): DRC(5,M)=SC(LMN) 3662 DBC(6,M)=(100*(SX(LMN)-SX(LST-NST)))\LHT :DBC(3,M)=ASTRT(LMN) :DBC(4,M)=AEND(LMN) 3663 DBC(7,M)=(100~(SY(LMN)-LINY))\LHT : DBC(9,M)=( 50~(32*Y(SNO(LMN)-1)\AY+BY-LINY))\LHT: IF LMN =l THEN DBC(8,M)=( 50*(3~Y(2)\AY+BY-LINY))\LHT ELSE DBC(8,M)=
( 50~(32~Y(SNO(LMN~ 2)\AY+BY-LINY))\LHT
3664 IF YX < SYX(LMN) THEN YX=SYX(LMN) 3665 IF YN > SYN(LMN) THEN YN=SYN(LMN) 3666 IF XX ~ SXX(LMN) THEN XX=SXX(LMN) 3667 IF XN > SXN(LMN) THEN XN=SXN(LMN) 3668 IF DBUG > 0 THEN LPRINT USING " #";MCHR,DBC(l,M),DBC(2,M),DBC(3,M),DBC(4,M),DBC(5,M),DBC(6,M),DBC(7,M),DBC(8,M),DBC(9,M) 3669 IF DBUG < 0 THEN LOCATE 10+M,27: PRINT USING " #";MCHR,DBC(l,M),DBC(2,M),DBC(3,M),DBC(4,M),DBC(5,M),DBC(6,M),DBC(7,M),DBC(8,M),DBC(9,M) 3670 NEXT M :GOSUB 3700 3671 NPOS=(2+(XX+XN)\16-IMARGN)\2 3672 REM PRINT n MCHR,NPOS,CHAR,ED" ,MCHR,NPOS,CS$,ED :INPUT IJK
3673 IF ED = l THEN NPOS=0: AS$(MCHR)=CS$
3674 IF NPOS > 0 THEN IF NPOS < 40 THEN AS$(NPOS)=CS$

3675 IF ED <> 1 THEN LOCATE (LINY-LHT+1)\8,(XX~XN)\16tl :PRINT CS$

13~2~;72 3680 S~Y(MCHR)=XX : SXN(MCHR)=XN
3682 SYX(MCHR)=YX : SYN(MCHR)=YN
3688 MCHR=MCHR+1: NST=1: XX1=XX: XX=-1: XN=1000: YX1=YX: YX=-1: YN=1000 3710 R1=16000 :M3=0 :IF NDBT=0 THEN GOTO 3900 3715 FOR M=1 TO NDBT
3720 IF DN~M) <> NST THEN GOTO 3790 :REM CHECK NUMBER OF STROKES
3725 M2E=9 : IF LINY = 0 THEN M2E=6 3730 R=0 : FOR M1 =1 TO NST
3735 FOR M2=1 TO M2E
3738 DR=ABS(D(M2,M3+M1)-DBC(M2,M1)) 3740 IF M2 < 2 THEN GOTO 3744 ELSE IF M2 > 4 THEN GOTO 3744 3741 IF DR ~ 128 THEN DR=ABS(DR-256): GOTO 3741 :REM USE 64 FOR DIRECTION INDEPENDENCE
3742 IF ABS(D(5,M3~M1)~ > 20 THEN DR=20*DR\(ABS(D(5,M3+M1))) 3744 IF DR > 300 GOTO 3790 3748 R=R+DR
3749 IF R > R1 &OTO 3790 3750 NEXT M2 : NEXT M1 3780 MS1=M : R1=R
3790 M3=M3+ DN(M) :NEXT M

3803 CS$=CHR$t DC( MS 1 ) ) 3805 IF DBUG <> 0 THEN LOCATE 19,1 :PRINT R1 ,MSl ,CS$

3810 IF R1\NST > ACPT GOTO 3900 :REM CHARACTER NOT FOUND

3902 IF LERN = 0 THEN CS$=CHR$(2): RETURN
3904 IF KYBD=0 THEN LOCATE 23,1 :INPUT "CHARACTER NOT UNDERSTOOD, PLEASE TYPE IT IN: ",CS$
3906 IF KYBD = 0 THEN LOCATE 23,1 :PRINT "
,, 3910 IF KYBD=1 THEN GOSUB 11400 3912 IF KYBD =1 THEN GOSUB 9600 3914 IF KYBD =1 THEN GOSUB 11600 : CS$=CHR$(MSEL) 3915 IF CS$="~" THEN GOTO 3960 3917 IF ED=1 THEN RETURN
3920 IF NDBT = 300 THEN PRINT "Too Many Symbols": STOP
3926 NDBT=NDBT+1 : DN(NDBT)=NST : DC(NDBI`)=ASC(CS$) 3930 IF M3+NST > 800 THEN PRINT "Too Many Strokes" :STOP
3936 FOR Ml=l TO NST: FOR M2=1 TO 9 3940 D(M2,M1+M3)=DBC(M2,M1) : NEXT M2 : NEXT M1 3960 CS$=

4010 FOR L=2 TO NSTRK
4014 IF X(SNO(L-1)) < 0 THEN GOTO 4090 4016 IF SL(L-1) < 4 THEN GOTO 4100 4020 ALNO=(ABSlABS(XlSNO(L)))-ABS(X(SNO(L-1))))+ABS(Y(SNO(L))-Y(SNO(L-1)))) 4021 REM LOCATE 1,1: PRINT "L,ALNO",L,ALNO
4022 IF ALNO > 100 THEN GOTO 4090 : REM TOO FAR AWAY
4024 ALNO= 8*ALNO\tSNO(L)-SNO(L-1)) 4026 DD =ABS(ABS(X(SNO(L-1)))-ABS(X(SNO(L-1)+2)))~ABS(Y(SNO(L-1))-Y(SNO(L-1)l2)) 4027 REM PRINT "L,DD,ALNO",L,DD,ALNO
4028 IF DD > ALNO THEN GOTO 4090 : REM TOO FAR AWAY
4030 IR1=80*SC(L)\SL(L~ : IR2=80*SC(L-1)\SL(L-1) 4031 REM PRINT "L,IR1,IR2",L,IR1,IR2 ~3~2~2 4032 IF ABS(IRl) > 350 THEN GOTO 4040 :REM SMALL WIGGLE
4034 IF ABS(IR1) < 80 THEN GOTO 4038 :REM STRAIGHT LINE
4036 IF ABS(IR1-IR2) > ABS(IR1~IR2)\3 THEN GOTO 4090 ELSE GOTO 4050 : REM TOO DIFFERE~T CURVATURE
4038 IF ABS(IR2) > 80 THEN GOTO 4036 ELSE IF IR1*IR2 < -2000 THEN GOTO 4090 :REM TOO DIFFERENT CURVATURE

4040 IF ABS(IR2) < 350 THEN GOTO 4036 ELSE IF IR1*IR2 < 0 THEN GOTO 4090 4050 ASTND=ABS(ASTRTt L)-AEND( L-l)) 4051 REM PRINT "ASTND"~ASTND
4052 IF ASTND > 1 28 THEN ASTND=ABS(ASTND-256): GOTO 4052 4054 IF ASTND > 64 THEN GOTO 4090 ELSE IF ASTND > DD*(ABS(IR1)~ABS(IR2))\40 THEN GOTO 4090 4101 REM PRINT IlCOMBININGllrL~L-1 4110 L1=L-1 :SLL=SL(L1)+SL(L) 4115 IF SLL = 0 THEN LOCATE 23l1 :PRINT "TWO STROKES WITH NO LENGTH" :STOP
4120 IF SXX(L~ > SXX(Ll ) THEN SXX(L1)=SXX(L) 4122 IF SXN(L) < SXN(L1) THEN SXN(L1)=SXN(L) 4124 IF SYX(L) > SYX(L1) THEN SYX(L11=SYX(L) 4126 IF SYN(L) < SYN(L1) THEN SYN(L1)=SYN(L) 4130 SX(L1)=(SL(L1)*SX(L1)+SL(L)~SX(L))/SLL
4133 SY(Ll )=(SLIL1)*SY(L1)+SL(L)*SY(L))/SLL
4137 SA(L1)=(SL(L1)~SA(L1)+SL(L)*SA(L))/SLL
4140 SL(L1)=SLL ~DD
4150 SC(L1)=SC(L1 )+SC(L)+( ISC(L1)+SC(L))*DD)\SLL
4160 SNO(L11=SNO(L) :AEND(L1)=AEND(L) 4170 NSTRK=NSTRK-1 : IF NSTRK < L THEN RETURN
4180 FOR LL=L TO NSTRK
4185 L1=LL+1 :SXX(LL)=SXX(L1) :SXN(LL)=SXN(L1) :SYX(LL)=SYX(L1) :SYN(LL)=SYN(L1)4187 SX(LL)=SX(L1) :SY(LL)=SY(L1) :SA(LL)=SA(L1) :SC(LL)=SC(L1) SNO(LL)-SNO(L1)4189 SL(LL)=SL(L1): ASTRT(LL)=~STRT(L1): AEND(LL)=AENDlL1) 4210 M2=0 4 220 FOR M= 2 TO NP STEP 2 : M 1 =M- 1 4230 IF X(Ml ) > 0 GOTO 4240 4235 M2=M2~1 :X(M2)~X(M1) :Y(M2)=Y(M1) :GOTO 4280 4240 IF X(M) > O GOTO 4250 4245 M2=M2+1 :X(M2 )=X(M) :Y(M2 )=Y(M) :GOTO 4280 4250 IF ABS(X(M)-X(M1)) > 30 THEN GOTO 4280 4260 IF ABS(Y~M)-Y(M1)) > 30 THEN GOTO 4280 4270 M2=M2+1 :X(M2)=(X(M)+X(M1))\2 :Y(M2)=(Y(M)+Y(M1))\2 4283 X(M21=X(NP) 4285 NP=M2 43 4 2 XCH=0 : I F NSTRK < 2 THEN RETURN
4345 FOR L=2 TO NSTRK
4350 IF SXN(L) > SXN(L-1) THEN GOTO 4380 4355 XCH=1 :L1=L-1 4360 ST=SXX(L1) :SX~(L1 )=SXX(L) :SXX(L)=ST
4361 ST=SXN(L1) :SXN(L1)=SXN(L) :SXN(L)=ST
4362 ST=SYN(L1) :SYN(L1)=SYN(L) :SYN(L)=ST
4363 ST=SYX(L1) :SYX(Ll )=SYX(L) :SYX(L)=ST
4364 ST=SX(L1) :SX(L1 )=SX(L) :SX(L)=ST
4365 ST=SY(L1) :SY(Ll)=SY(L) :SY(L)=ST
4366 ST=SA(Ll) :SA(L1)=SA(L) :SA(L)=ST

't,~ 2~

4367 ST=SC(Ll) :SC(Ll)=SC(L) :SCIL)=ST
4368 ST=SLILl) :SL(Ll)=SL(L) :SL(L)=ST
4369 ST=SNO(Ll) :SNO(Ll)=SNO(L) :SNO(L)=ST

4390 IF XCH = 0 THEN RETURN ELSE XCH=0 :GOTO 4345 6105 LERN=l :J=3: JJ=J : FOR I=1 TO 40 :AS$(I)=" " :NEXT I
6110 LINY=8*(JJ+3)-1 6120 LINE (0,LINY-LHT-8)-(639,LINY+LHT\2),0,BF
6130 LINE (8*IMARGN-l,LINY)-(639,LINY-LHT),l,B
6140 LINE (607,LINY)-(639,LINY-LHT),l,BF
61S0 IF SWTPN = -1 THEN GOSUB 7100 ELSE GOSUB 8600 :REM TOUCH TECH SCREEN IN ASCII @ 9600 6151 IF SWTPN = 1 THEN GOSUB 7300 6155 IF NP < 8 THEN GOTO 6190 6180 LOCATE 18,IMARGN: FOR I=l TO 40: PRINT AS$(I);: NEXT I

6190 FOR I=l TO 4 6192 IF AS$1I) = "@" THEN RETURN

6201 XX=SXX(l): XN=SXN(1): YX=SYX(l): YN=SYN(1) 6202 XP=lXN+XX)/2: YP=(YN~YX)/2 :REM AVE CHARACTER POSITION
6203 I-INT(XP/8)+1: J=INT(YP/8)+1 :ISAV=I: JSAV=J: REM CONVERT X,Y TO I,J
6204 ML=LL(J): Ml=ML+I-IMARGN :REM CALC A ARRAY INDEX OF LETTER AT I,J
6205 IF A$(ML)=" " THEN Ml=Ml~l 6206 IF A$(ML)=CR$ THEN Ml=Ml+l 6207 MSAV=Ml 6210 JJ=JSAV : FOR I=l TO 40 :AS$(I)-" " :NEXT I
6215 LINY=8*(JJ+3)-1 6220 LINE (0,LINY-LHT-8)-(639,LINY+LHT\2),0,BF
6230 LINE (8*IMARGN-l,LINY)-~639,LINY-LHT),l,B
6240 LINE (607,LINY)-(639,LINY-LHT),l,BF
6250 IF SWTPN = -1 THEN GOSUB 7100 ELSE GOSUB 8600 :REM TOUCH TECH SCREEN IN ASCII @ 9600 6251 IF SWTPN = 1 THEN GOSUB 7300 6255 IY NP < 8 THEN GOTO 6270 6258 IF DBUG <> 0 THEN LOCATE 22,IMARGN: FOR I=l TO 40: PRINT AS$~I);: NEXT I

6270 JB=0: J=l 6271 REM LOCATE 16,1: FOR I=l TO 40: PRINT AS$tI);: NEXT I
6272 IE=2 :FOR I=40 TO 2 STEP -1 : IF AS$(I) <> ~ " THEN IE=I+l : GOTO 6274 6274 FOR I=2 TO IE
6275 IF AS$(I) <> " " THEN GOTO 6280 6276 JB=JB+l 6278 IF JB < 3 THEN GOTO 6288 6280 J=J+l: JB-0 6282 AS$(J)=AS$(1) 6289 REM LOCATE 17,1: FOR I=l TO 40: PRINT AS$(I);: NEXT I
6290 AS$(J+l)=" "
6295 IF J < 2 THEN IF AS$(1) =" " THEN LOCATE 18,1 : PRINT "NO LETTERS, ~Y AGAI
N" :GOTO 6210 6300 MD=J+l : M3=MSAV : I=ISAV : J=JSAV
6310 REM LOCATE 20,1: FOR I=l TO 40: PRINT AS$(I);: NEXT I

~ 2572 ``-6510 XX=SXX(1): XN=SXNI1): YX=SYX(1): YN=SYN(1) 6520 XP=(XN+XX)~2: YP=(YN+YX)/2 :REM AVE CHARACTER POSITION
6530 I=INT(XP/8)+1: J=INT(YP/8)+1:REM CONVERT X,Y TO I,J
6540 ML=LL(J): Ml=ML+I-IMARGN :REM CALC A ARRAY INDEX OF LETTER AT I,J
6550 IF A$(ML)=" " THEN Ml=Ml+l 6560 IF A$(ML~=CR$ THEN Ml=Ml+l 6570 M2=Ml 66g0 GOTO 200 6710 XX=SXX(1): XN=SXN(1): YX=SYX(1): YN=SYN(1) 6720 XP=(XN+XX)/2: YP=(YN+YX)/2 :REM AVE CHARACTER POSITION
6730 I=INT(XP/8)+1: J=INT(YP/8)+1:REM CONVERT X,Y TO I,J
6740 ML=LL(J): Ml=ML+I-IMARGN :REM C~LC A ARRAY INDEX OF LETTER AT I,J
6750 IF A$(ML)=" " THEN Ml=Ml+l 6760 IF A$(ML)=CR$ THEN Ml=Ml+1 6770 A$(M1)=AS$(1) :LOCATE J,I :PRINT AS$(1) 6910 XX=SXX(l): XN=SXNil): YX=SYX(l): YN=SYN(l) 6920 XP=(XN+XX)/2: YP=(YN+YX)/2 :REM AVE CHARACTER POSITION
6930 I=INT(XP/8)+1: J=INT(YP/8)+1:REM CONVERT X,Y TO I,J
6940 ML=LL(J): Ml=ML+I-IMARGN :REM CALC A ARRAY INDEX OF LETTER AT I,J
6950 IF A$(ML)=" " THEN Ml=Ml+1 6960 IF A$(ML)=CR$ THEN Ml=Ml+l 6970 AS$(2)=AS$(1) 6980 M3=Ml :MD=l 7010 OPEN "I",#l,"POINTS.DAT"
7020 INPUT #1,AX,BX,AY,BY

7110 INPUT #1,NP
7120 FOR N=l TO NP
7130 INPUT #1,X(N),Y(N) 7133 I F I FAVE = 1 THEN GOSUB 4200 7134 FOR N=l TO NP
7135 IF X(N) > 0 THEN I=32~X(N)/AX+BX ELSE I=-32*X(N)/AX+BX
7136 J=32*Y(N)/AY+BY
7137 PSET(I,J) 7148 IF DBUG > 5 THEN FOR N=l TO NP: LPRINT N,X(N),Y(N):NEXT N
7149 IF DBUG <> 0 THEN LOCATE 20,2 :PRINT "NP=",NP

7210 OPEN ~O",#1,~POINTS.DAT"
7220 PRINT #1,AX,BX,AY,BY

7310 PRINT #l,NP
7320 FOR N=l TO NP
7330 PRINT #1, USING " ##"; X(N),Y~N) 7~40 NEXT N

8600 REM TT ACQUIRE POINTS IN ASCII @ 9600 WITH INSERT
8603 M=20 8605 IF LOC(2) > 0 THEN IPUT$=INPUT$(1,2) : GOTO 8605 8606 PRINT #2,"G" :N=0 8610 IF LOC~2) < 40 THEN GOTO 8610 8620 NU=0: INPUT #2,XP,YP :INPUT #2,XP,YP :INPUT #2,XPA,YPA :INPUT #2,XPo,YPo 8630 N=N+1: XPA=(XPA+XP0)\2: YPA=(YPA+YP0)\2: XP0=XPA: YP0=YPA: X(N)=XPA: Y(N)=YPA
8635 IF 32*XPA\AX+BX > 607 THEN GOTO 8695 8640 INPUT #2,XP,YP
8653 XPA=(XP+3~XPA)\4: YPA=(YP~3~YPA)\4 8657 IF ABS(XPA-XP0)+ABS(YPA-YP0) < 3 THEN GOTO 8672 8660 I=32~XPA\AX+BX:J=32*YPA\AY+BY:PSET(I,J) 8665 IF I > 607 THEN GOTO 86g5 8670 N=N+1 : X(N)=XPA :Y(N)=YPA: XP0=XPA: YP0=YPA
8672 IF LOC(2) > 9 THEN GOTO 8640 8675 MM=0 8680 MM=MM+1: IF LOC(2) > 9 THEN GOTO 8640 ELSE IF MM < M THEN GOTO 8680 8685 X(N)=-X(N): IF X(N) = 0 THEN X(N)=-1 8690 IF LOC(2) > 39 THEN GOTO 8620 ELSE NU=NU~1 ,;IF NU < 25000 THEN GOTO 8690 8695 PRINT #2,"S": NP=N
8696 IF DEBUG <> 0 THEN LOCATE 20,2 :PRINT "NP=",NP
8697 IF IFAVE = 2 THEN GOSUB 4200 8698 IF DEBUG <> 0 THEN LOCATE 20,12 :PRINT NP

9600 REM TT ACQUIRE POINTS IN ASCII @ 9600 WITH MENU
9603 M=20 9605 IF LOC(2) > 0 THEN IPUT$=INPUT$(1,2) : GOTO 9605 9606 PRINT #2,"G"
9610 II=0 :JJ=0 :N=0 9640 INPUT #2,XP,YP
9660 II=32~XP\A~+BX+II: JJ=32*YP\AY+BY+JJ: N=N+1 9670 IF N < 10 THEN GOTO 9674 9~72 I=II\10: J=JJ\10: N=0 :II=0: JJ=0 9673 LINE (I+1,J+1)-(I-1,J-1),1,B
9674 IF LOC(2) > 9 GOTO 9640 9675 MM=0 9680 MM=MM+1: IF LOC(2) > 9 THEN GOTO 9640 ELSE IF MM < M THEN GOTO 9680 9690 IF LOC(2) > 9 THEN GOTO 9610 ELSE NU=NU+1 :IF NU < 1500 THEN GOTO 9690 9695 PRINT #2,"S"

10700 REM SET UP TOUCH SCREEN FOR ASCII @ 9600 10710 OPEN "I",#2,"CAL.DAT"
10720 INPUT #2,AX,BX,AY,BY
10730 CLOSE #2 10740 OPEN "COM1:9600,N,8,1,CS0,DS0" AS #2 10750 PRINT ~2,"S"

11100 REM input selection menus 11101 REM mnum= no. of items 11102 REM Mtitl$=titles 11103 REM miO,mie,mjO,~je=start ~ end points ~or boxes 11105 IF KYBD=1 GOTO 11400 11110 LINE~MI0,MJ0)-(MIE,MJE),0,BF :LINE(MI0,MJ0)-(MIE,MJE),1,B
11115 XX=MI0 : MRATO=(MIE-MI0)\MNUM
11120 FOR K=1 TO MNUM : LINE (XX,MJ0)-tXX,MJE) 11130 MJA=(MJ0+MJE+8)\16+1 : LOCATE MJA,(XX~20)\8 : PRINT MTITL$(K) 11140 XX=XX+MRATO :NEXT K

11310 IF KYBD=1 GOTO 11600 11320 XX=0 : FOR K=1 TO MNUM : XX=XX+MRATO : IF I < XX THEN GOTO 11340 11340 MSEL=K

11405 JMENU=163 ~ 13~2~72 ~-11410 LINE(1,160)-(639,199),0,BF
11440 FOR I= 1 TO 26 :LOCATE 22,2~I : PRINT CHR$(I+64), : NEXT I
11450 FOR I= 1 TO 26 :LOCATE 24,2*I : PRINT CHR$(I+96), : NEXT I
11460 FOR I= 1 TO 10 :LOCATE 22,2~I+52 : PRINT CHR$(I+47), : NEXT I
11470 LOCATE 22,74 : PRINT ". ? ", 11480 LOCATE 24,54 : PRINT "\ / ~ + - ( ) , ; : ";CHR$(34);" $ &";
11482 FOR J=163 TO 195 STEP 16 : LINE(3,J)-(629,J) :NEXT J
11484 FOR I= 3 TO 635 STEP 16 : LINE(I,163)-(I,195) :NEXT I
11490 LOCATE 1 ,1 :RETURN
11600 REM keyboard select from ~enu 11620 MSEL=(I\8+1)\2 11640 IF J > 179 THEN GOTO 11700 11650 IF MSEL < 27 THEN MSEL=MSEL+64 : RETURN
11660 IF MSEL < 37 THEN MSEL=MSEL+21 : RETURN
11670 IF MSEL=37 THEN MSEL=46 : RETURN
11680 IF MSEL=38 THEN MSEL=94 : RETURN
11690 MSEL=63 : RETURN
11700 IF MSEL < 27 THEN MSEL=MSEL+96 : RETURN
11710 IF MSEL=27 THEN MSEL=92 : RETURN
11720 IF MSEL=28 THEN MSEL=47 : RETURN
11730 IF MSEL=29 THEN MSEL=42 : RETURN
11740 IF MSEL=30 THEN MSEL=43 : RETURN
11750 IF MSEL=31 THEN MSEL=45 : RETURN
11760 IF MSEL=32 THEN MSEL=40 : RETURN
11770 IF MSEL=33 THEN MSEL=41 : RETURN
11780 IF MSEL=34 THEN MSEL=44 : RETURN
11790 IF MSEL=35 THEN MSEL=59 : RETURN
11800 IF MSEL=36 THEN MSEL=58 : RETURN
11810 IF MSEL=37 THEN MSEL=34 : RETURN
11820 IF MSEL=38 THEN MSEL=36 : RETURN
11830 MSEL=38 : RETURN

12000 REM input output 12100 REM read in text 12110 OPEN "I", #1,"TEXT" :NC=0 12120 IF EOF(1) THEN CLOSE #1 : GOTO 12160 12130 INPUT #1, A1$ :KK=0 12140 FOR K=1 TO LEN(A1$) : KK=KK-~1 :A$(NC+KK)=MID$1A1$,K,1) 12143 IF LEN(A$(NC+XK)1=0 THEN KK=KK-1 12150 NC=NC+KK:IF NC < 1500 THEN GOTO 12120 12155 PRINT ~TOO MUCH TEXT" : STOP

12170 II=IMARGN : JJ=JTOP : NC1=1 : REM DISPLAY ALL TEXT
12175 CLOSE #1 12505 IF SWTPN <> 0 THEN CLOSE #1 12510 OPEN ~O",#1,"SYM.DAT"
12520 PRINT #1,NDBT
12530 M2=0 :FOR M=1 TO NDBT
1254~ PRINT #1, DN(M) DC(M) 12550 FOR Ml=M2+1 TO M2+DN(M) 12560 PRINT #1, D(1,M1) D(2,M1) D(3,M1) D(4 ,Ml ) D(5,M1) D( 6,Ml ) D( 7,M1 12570 NEXT Ml :M2=M2+DN(M) : NEXT M
12580 CLOSE #1 12710 OPEN "I",#1,"SYM.DAT"
12720 INPUT #1,NDBT
12730 M2=0 :FOR M=1 TO NDBT
12740 INPUT #1,DN(M),DC(M) 12750 FOR M1=M2+1 TO M2+ DN(M) ~L3~D2~72 12760 INPUT #l,D(l,Ml),D(2,Ml),D(3,Ml),D(4,M1),D(5,Ml),D(6,Ml),D(7,Ml) 12770 NEXT Ml :M2=M2+DN(M) : NEXT M
12730 CLOSE #l 30000 FOR I=l TO NSTRK:PRINT I,SNO(I),SX(I),SY(I),SL(I~,SA(I),SC(I):NEXT I
30010 FOR I=l TO NP:PRINT I,X(I),Y(I):NEXT I
30020 FOR I=l TO NSTRK:PRINT USING " #";I,SNO(I),SX(I),SY(I),SL(I),SA(I),SC(I):NEXT I
30030 FOR Ml=l TO NST :FOR M2=l TO 5 :PRINT Ml,M2,D(M2,Ml),DBC(M2,Ml):NEXT M2 :NEXT Ml ~ ~3~;~572 ~

APPENDIX III

A1 - angle of slope between Point M and M1 A2 - previous angle DA1 - change in angle (A1-A2) SEND - flag for end of Stroke ZX ~ double precision X position summation by arc length weighting ZY - double precision Y position summation by arc length weighting ZA - double precision angle summation by arc length weighting ZDA - double precision change in angle summation ZL - double precision length NSP - number of Points in Stroke, counter NSTR~ - number of Strokes XX - maximum X
XN - minimum X
YX - maximum Y
YN - minimum Y
M1 - Pointer to previous Point M2 - (1) minimum number of Points for which to adjust for 2~ angle M3 - (2) minimum number of Points for which to calculate change in change in angle NLONG - counter (not used) M - Pointer to Point being considered NP - number of Points X - array of X coordinate Y - array of Y coordinate DX - change in X
DY - change in Y
ADX - absolute value of DX
ADY - absolute value of DY
DS - pseudo arc length ADX + ADY
AY - calibration multiplier for vertical (Y) direction, e.g.
AY ' O mean coordinate system true downward ADA - running average change in angle DA2 - previous change in angle ASTRT - array for starting angle of Stroke SZL - single precision Stroke length SNO - array of number of the 1st Point for each Stroke LHT5 - height between lines divided by S in display coordinates used as a measure SL - array of Stroke lengths sealed to height between lines AEND - array of angles at end of Strokes SC - array of angle changes for eachs troke AZA - average angle through Stroke SX - array of averages centroid X coordinate for each Stroke SY - array of averages centroid Y coordinate for each Stroke SA - array of averages angle (slope) co~rdinate for each Stroke SXX - array of maximum X coordinate for each Stroke SXN - array of minimum X coordinate for each Stroke SYN - array of minimum Y coordinate for each Stroke SYX - array of maximum Y coordinate for each Stroke DBUG - debugging flag for printing INPUT - string of input bytes to be rejected XP, YP - input coordinates XPA - average 2 Points in X direction YP~ - average 2 Points in Y direction XPO - initial X average on pan down YPO - initial Y average on pan down I - display pixel corresponding to X coordinate input ~30~

J - display pixel corresponding to Y coordinate input N - counter of input Points MM - counter for timing pan up NU - counter for timing pan up

Claims (33)

1. Apparatus for recognizing Handwritten Symbols and respectively displaying Handwritten and Font Symbols and executing Editing Functions or other commands on a screen comprising:
(a) A visual display screen having the graphic capability to display Font Symbols and means to execute Editing Functions;
(b) Hand-held means to write or draw Handwritten Symbols on or over said screen;
(c) Means to display a true representation of the Handwritten Symbols on said screen as they are created;
(d) Digitizing means to sense the position of said hand-held means and to convert the same into a series of electrical signals defining position, size and shape of each Handwritten Symbol;
(e) Means to compare predetermined characteristics of each digitized Handwritten Symbol with a database of predetermined characteristics of Font Symbols and Editing Functions to assess the identity of each Handwritten Symbol;
(f) Means to (i) convert each Handwritten Symbol to an Editing Function or other commands or a predetermined Font Symbol and (ii) execute the Editing Function or other commands or display the Font Symbol on the screen in close proximity to the screen area in which the corresponding Handwritten Symbol was originally entered, as the case may be;
(g) Means to display predetermined combinations of Font Symbols in the form of text or forms on said screen, whereby Handwritten Symbols can be used to input information to complete a form, to edit a predetermined text, or both, as the case may be; and (h) Means operative upon execution of a predetermined command to create a window on said screen, free of text or other information, for entering Handwritten Symbols.

2. Apparatus as set forth in Claim 1 wherein said apparatus comprises a portable unit having dimensions up to about 16" x 16" x 4", a weight of up to about 15 pounds and is adapted to include a self-contained power supply.

3. Apparatus as set forth in Claim 1, including means to display predetermined Font Symbols including Editing Symbols on said screen, so as to permit Handwritten Symbols representing each predetermined Pont Symbol and Editing Symbol to be manually defined on the screen and means to identify the manually defined Handwritten Symbol with the corresponding predetermined Font Symbol in said database.

4. Apparatus as set forth in Claim 3, including means to modify said database when a Handwritten Symbol causes an erroneous Font Symbol to be displayed on the screen or command to be performed, as the case may be.

5. Apparatus as set forth in Claim 1, including areas on said screen sensitive to touch to cause predetermined functions to be performed.

6. Apparatus as set forth in Claim 1, wherein said screen is substantially flat and adapted to be used in a substantially horizontal position.

7. Apparatus as set forth in Claim 1, including Softkeys on said screen and means to execute operational commands in response to touching any of said Softkeys.

8. An apparatus as claimed in Claim 1 wherein said command means (h) is a caret.

9. An apparatus as claimed in Claim 1 wherein said command means (h) is the writing of one or more horizontal or vertical lines through displayed Font Symbols on said screen.

10. An apparatus as claimed in Claim 1, wherein said window can be of various sizes and shapes.

11. An apparatus as claimed in Claim 1, wherein said window can be used to insert graphic images as well as Handwritten Symbols.

12. A microprocessor-based process for recognition, translation and display of Handwritten Symbols and execution of Editing Functions and other commands comprising the steps of:
(a) Creating a personalized database for each individual user of the process by having the user initially input a Handwritten Symbol for each character corresponding with a Font Symbol to be displayed or Editing Function or other command to be executed;
(b) Determining a unique set of Stroke characteristics to characterize each such symbol and storing it in the database;
(c) Writing or drawing Handwritten Symbols on a computer screen with a stylus;
(d) Digitizing each Handwritten Symbol to identify the x, y coordinates of a multiplicity of Points into Strokes defining the Handwritten Symbol;
(e) Processing the digitized characteristics of each Stroke of a Handwritten Symbol to determine the predetermined characteristics of the Handwritten Symbol;
(f) Each of steps (b) and (e) comprising a determination of the (i) length of the stroke, (ii) average slope of the stroke, (iii) the stroke centroid's height above the base line, (iv) rate of change in slope of Stroke and (v) comparison of the location of the centroid of each Stroke with the centroid of the Handwritten Symbol.

(g) Searching the database to find a "hit", a perfect or the closest correspondence to the characteristics of a Font Symbol;
(h) Displaying the Font Symbol or performing the command most closely associated with the "hit" characteristics.

13. A process as set forth in Claim 12, including the additional steps of:
(a) Determining if the Font Symbol displayed or command performed is an error; and (b) If there is an error, re-inputting a Handwritten Symbol for the desired Font Symbol or command to modify the database.

14. A process as set forth in Claim 12, including the additional step of:
(a) Substantially contemporaneously displaying the Handwritten Symbol on the screen as it is being written or drawn.

15. A process as set forth in Claim 12, wherein step (g) comprises:
(a) Determining the value of each of the five characteristics;
(b) Subtracting the database value of the characteristic from the newly-measured value;
(c) Scaling the absolute values of each measurement to make each of the five measurements reasonably equivalent to the others;

(d) Adding all five values;
(e) If a predetermined threshold is exceeded, discarding the comparison and creating an error message; and (f) Searching the database to find a numerical "hit", or, if not feasible, the closest numerical match between the database value and the newly inputted value.

16. A process as set forth in Claim 15, wherein the program for step (f) requires less than 6K of machine memory.

17. A process as set forth in Claim 12, wherein said Handwritten Symbols include Editing Symbols and said process includes recognition of the Editing Symbols drawn on the screen and executing the Editing functions represented.

18. A process as set forth in Claim 12, in which text in Font Symbol format is displayed on the screen, and including the steps of:
(a) Creating a window on the screen proximate to, but not overlying, an area of said text to be edited;
(b) Inputting and displaying said Handwritten Symbols in said window;
(c) Displaying the Font Symbols corresponding to said Handwritten Symbols in close proximity to said Handwritten Symbols.

19. A process as set forth in Claim 12, including the steps of:

(a) Creating one or more Softkeys on said screen to cause the microprocessor to perform operational functions; and (b) Touching one or more of said Softkeys to execute the corresponding functions.

20. A process as set forth in Claim 12, including the steps of determining the x,y coordinates of from about 100 to 200 points per inch and from about 100 to 200 points per second in characterizing said Handwritten Symbols.

21. A process as set forth in Claim 12, wherein the end of a Stroke is determined by the detection of a change in angle or direction exceeding a maximum set threshold.

22. Apparatus for recognizing symbols and editing text comprising:
a display which includes apparatus for providing output signals, each output signal indicative of a plurality of successive positions on said display selected by a hand-held stylus:
a computer, coupled to said display, configured to receive said signals, to recognize at least some of said output signals as corresponding to at least one of a plurality of font symbols, to recognize at least some of said output signals as corresponding to at least one of a plurality of editing symbols, to control said display causing it to display a computer-generated symbol when said recognized symbol is a font symbol and to execute an editing function when said recognized symbol is an editing symbol.

23. A method for recognizing symbols and editing text comprising:
providing a computing device which includes a display, said display having apparatus for providing output signals, each output signal indicative of a plurality of successive positions on said display selected by a hand-held stylus;
receiving said signals in said computing device, using said computing device to recognize at least some of said output signals as corresponding to at least some of a plurality of font symbols;
using said computing device to recognize at least some of said output signals as corresponding to at least some of a plurality of editing symbols;
displaying a predetermined symbol on said display when aid recognized symbol is a font symbol and executing an editing function when said recognized symbol is an editing symbol.

24. A method for recognizing symbols and editing text comprising:
providing a computing device which includes a display said display having apparatus for providing handwritten symbol output signals, each handwritten symbol output signal indicative of a plurality of successive positions on said display selected by a hand-held stylus:
receiving said signals in said computing device:
using said computing device to recognize at least some of said output signals as corresponding to at least some of a plurality of font symbols:
storing in said computing device, data corresponding to editing function symbols;
using said computing device to compare said handwritten symbol output signals with said data corresponding to editing function symbols and to recognize at least some of the handwritten symbol output signals as corresponding to at least some of a plurality of editing symbols;
displaying a predetermined symbol on said display when said recognized symbol is a font symbol; and executing an editing function when said recognized symbol is an editing symbol.

25. A method for recognizing handwritten symbols comprising:
providing a display screen;
displaying a plurality of characters or symbols on at least a first area of said display screen;
writing a handwritten symbol over at least a portion of said first area of said display screen;
digitizing said handwritten symbol to provide a digitized symbol;
correlating said digitized symbol with at least one of a plurality of predetermined symbols, including a plurality of editing symbols by comparing characteristics of said digitized symbol with stored characteristics of at least some of said plurality of predetermined symbols, to provide one of said plurality of predetermined symbols as a designated symbol which is correlated with said handwritten symbol;
executing at least a first of said plurality of editing functions when said designated symbol was written over at least one of said displayed characters or symbols; and executing at least a second of said plurality of editing functions when said designated symbol is one of said plurality of editing symbols.

26. A method for recognizing handwritten computer commands comprising:

providing a computer having at least a display screen and a memory, and capable of executing a plurality of commands to perform operations on data;
storing data in a plurality of memory locations in said memory;
writing a handwritten command symbol over a location on said display screen digitizing said handwritten symbol to provide at least one digitized symbol, and an indication of said location on said display screen;
correlating said at least one digitized symbol with at least one of a plurality of predetermined symbols, by comparing characteristics of said digitized symbol with stored characteristics of at least some of said plurality of predetermined symbols, to provide at least one designated symbol, said at least one designated symbol being correlated with at least one of said plurality of commands to perform operations on data:
selecting at least a first portion of said data, said selecting being based on said location of said handwritten symbol on the display screen:
executing said at least one computer command to perform an operation on said selected data.

27. A method, as claimed in claim 26, wherein said data corresponds to font symbols and wherein font symbols corresponding to at least some of said data are displayed on said display screen and wherein:
said step of selecting at least a first portion of said data includes selecting data corresponding to at least one displayed font symbol which is adjacent to said location of said handwritten symbol on the display screen.

28. A method, as claimed in claim 27, wherein said step of executing at least one computer command includes inserting data in said memory, at least some of said inserted data corresponding to at least a first font symbol, and further comprising:
displaying at least said first font symbol adjacent to said location of said handwritten symbol on the display screen.

29. A method, as claimed in claim 27, wherein said step of executing at least one computer command includes adjusting a margin of said displayed font symbols.

30. A method, as claimed in claim 27, wherein said step of executing at least one computer command includes deleting at least one displayed font symbol.

31. A method, as claimed in claim 27, wherein said step of executing at least one computer command includes moving at least one displayed font symbol,

32. Apparatus, as claimed in claim 22, wherein said computer is further configured to request further input from said hand-held stylus if at least some of said output signals are not recognized as corresponding to at least one of a plurality of editing symbols.

33. Apparatus as claimed in claim 22, wherein said computer is further configured to include a database of stroke sequences and corresponding symbols and to add a new symbol to the database when at least some output signals are not recognized as corresponding to at least one of said plurality of editing symbols or font symbols.