SDrive-MAX
==========

SDrive-MAX is a new disk drive and tape emulator for Atari 8bit computers
based on sdrive-ng ported to arduino and enhanced with a touchscreen display
for controlling. So it can work without sdrive software on the Atari, but
could be used anyway. Changing disk images during live operation is one of the
most important features, i think.

What do you need?

- an arduino UNO with atmega328p
- an Elegoo 2,8" TFT-Touchscreen Shield or similar with ILI9341 compatible
  controller using 8bit parallel mode(i think, that one from the adafruit
  project is the same). Touchlines must be wired as followed:
  Update! Touchlines are now auto detected!

  X+ <-> 8
  X- <-> A2
  Y+ <-> A3
  Y- <-> 9

  The other lines are always the same, as far as i could see
  (TFT-Data 2-9, -Ctrl. A0-A4, SD 10-13). In doubt, ask!

  Update! Other displays with one of the following chip are now also supported:
  ILI9329, ILI9340, HX8347G, HX8347I
- a diode 1N4148 or similar - Update!
  better use a schottky diode
- a micro SD-Card(SD or SDHC)
- some cable and connectors to Atari's SIO-Port
- avrdude Software for firmware programming

Wirering Arduino <-> Atari-SIO:

  TXD <-> Pin 3 (Data-In, over the diode, cathode to arduino)
  GND <-> Pin 4	(Ground)
  RXD <-> Pin 5 (Data-Out)
  A5  <-> Pin 7 (Command)
* +5V <-> Pin 10 (+5V/Ready)

*Optional, if you want power from Atari, but then you can't use Display
 while Atari ist powered off!
 Update! We strongly recommend to use an external power supply, because the
 Atari is specified at 50mA max., and Sdrive-MAX needs about 150mA!
 Voltage drop on the SIO lines will make curious problems especially in
 conjunction with other devices!

Firmware programming:

First use the eeprom-writer.hex to set the correct values to the EEPROM!
Wait until the writer has done, then programm the SDrive.hex into the flash.
That's it!

Display usage:

- On first start follow touching the calibration crosses. You can redo this
  at any time by hold touching during startup. This have to be also done,
  if you have changed the display rotation.
- Press drive buttons in the middle to select the actual boot drive (D1:)
  (on startup always the internal drive D0: with SDRIVE.ATR loaded is selected
  for old sdrive(-ng) compatibility)
- Press drive buttons on the left do deactivate the drive
- Press dirve buttons on the right at the disk logo to insert an image
- D0: can only be selected as boot drive, not changed
- If you want to boot from an external drive, select an empty drive slot as D1:!
- Press on the New button will create a new image on the selected drive
  during the next format command
- Press on the output window at bottom will open SIO debug mode. To close
  press anywhere on the screen
- File select window should be self descripting
- To save selected images on EEPROM, press the Cfg button, highlight
  the SaveIm button, and press Save
- If you want also to boot from drive 1 by default, highlight the BootD1
  button too before pressing Save
- The "1050" option in Cfg menu uses timing for 1050 drive on ATX files,
  instead of 810
- Do not power off, while the red signal on top left of the screen appears,
  then the write cache was not written to SD!

Tape operation:

- point the actual boot drive (D1:) to an empty slot(some loader won't start,
  if a disk drive is active)
- press Tape: button and select an image of type FUJI or raw binary
- hold down the START & OPTION keys on the atari and power on
- press any key to start tape operation after the burp
- and press the Start button on sdrive-max immediately
- if a multi stage loader requires a key press to go on, then do this quick,
  because the tape does not hold! (we have no motor signal connected)
- to stop hold down the Start button until the next block loading
- the tape is automatically rewind, so you could start again from beginning
  at this point
- press the Turbo button, if you want to enable a 1000 baud transmission
- exit ends the tape emulation
- you can also load basic files with CLOAD, if you are lucky :)

(by KBr from forum64.de)