A simple Python based 8085 assembler.
usage: assembler.py [-h] [-L] [-A] [-B] [-I] [-H] [-C] [-s] [-b] [-t] [-o OUT] source
A simple 8085 assembler.
positional arguments:
source source file
options:
-h, --help show this help message and exit
-L, --lineNum include the line number in output
-A, --address include the address in output
-B, --label include the labels in output
-I, --instruction include the instructions and arguments in output
-H, --hex include the hex code in output
-C, --comment include the comments in output
-s, --standard equivalent to -A -B -I -H -C
-b, --bin outputs only binary data
-t, --trs100 creates basic loader for TRS-80 Model 100
-o OUT, --out OUT output file name (stdout, if not specified)
The assembler is case sensitive.
Comments begin with semicolons.
mvi A, 0x5C ; This is a comment8 and 16-bit constants are given in hex. 8-bit constants must have two digits, and 16-bit constants must have 4-digits.
mvi A, 0x0C
mvi A, 0C ; The "0x" is optional
mvi A, 'a' ; letters can be used as input, usage is ascii
mvi A, 7 ; Illegal. 8-bit constants must have two digits
lxi H, 0x03B7
lxi H, 03B7 ; The "0x" is optional
lxi H, 3B7 ; Illegal. 16-bit constants must have four digitsIf an 8-bit constant is given where a 16-bit constant is expected, the 8-bit constant will be converted to a 16-bit constant, with the upper 8-bits all zero.
jnz 0x3FC7 ; Jump-not-zero to 0x3FC7
jmp FF ; JMP takes a 16-bit argument, but given 8-bits. Will JMP to 0x00FFLabel definitions may be any string ending with a colon, where the string does not match the pattern of an 8 or 16-bit constant.
; Example
;*******************************************************************************
mvi A, 0x5C
Foo: dcr A ; Label definition
jnz Foo ; Jump-not-zero to Foo
;*******************************************************************************
mvi A, 0x5C
FD: dcr A ; Illegal. Label definition cannot match hex constant format
jnz FDSets the origin to the given address. Only forward movement of the origin is permitted.
; Example
;*******************************************************************************
mvi A, 55
out 42
jmp Start
Start: org 0x44
mvi A, 32
out 42
;*******************************************************************************
; Assembles to the following:
Address Label Instruction Hex Code
--------------------------------------------------------------------------------
0x0000 mvi A, 55 0x3E
0x0001 0x55
0x0002 out 42 0xD3
0x0003 0x42
0x0004 jmp START 0xC3
0x0005 0x44
0x0006 0x00
0x0044 START: mvi A, 32 0x3E
0x0045 0x32
0x0046 out 42 0xD3
0x0047 0x42 ; Example
;*******************************************************************************
org 0x44
mvi A, C7
out 44
org 0x00 ; Illegal. Cannot move origin backwards
jmp 0x0044Writes one or more data bytes sequentially into memory.
; Example
;***********************************************************
mvi A, 33
db 0x44, 0xFE, 0x9C
hlt
;***********************************************************
; Assembles to the following:
Address Instruction Hex Code
------------------------------------------------------------
0x0000 mvi A, 33 0x3E
0x0001 0x33
0x0002 db 0x44
0x0003 db 0xFE
0x0004 db 0x9C
0x0005 hlt 0x76 Writes one or more char bytes sequentially into memory. At the end 0x00 can be added with \0. Some of the ASCIIZ control charactgers are supported.
; Example
;***********************************************************
mvi A, 33
dm "Hello\0"
hlt
;***********************************************************
; Assembles to the following:
Address Instruction Hex Code
------------------------------------------------------------
0x0000 mvi A, 33 0x3E
0x0001 0x33
0x0002 dm 0x48
0x0003 dm 0x65
0x0004 dm 0x6C
0x0005 dm 0x6C
0x0006 dm 0x6F
0x0007 dm 0x00
0x0008 hlt 0x76 Equates a symbol with a number.
; Example
;***********************************************************
foo equ 0xC5F3
mvi A, 33
lxi H, foo
;***********************************************************
; Assembles to the following:
Address Instruction Hex Code
------------------------------------------------------------
0x0000 mvi A, 33 0x3E
0x0001 0x33
0x0002 lxi H, FOO 0x21
0x0003 0xF3
0x0004 0xC5 Defines and reserves the next n-bytes for storage.
; Example
;*******************************************************************************
jmp END
Storage: ds 0x05
lda Storage
END: out 42
;*******************************************************************************
; Assembles to the following:
Address Label Instruction Hex Code
--------------------------------------------------------------------------------
0x0000 jmp END 0xC3
0x0001 0x0B
0x0002 0x00
0x0008 STORAGE: lda STORAGE 0x3A
0x0009 0x03
0x000A 0x00
0x000B END: out 42 0xD3
0x000C 0x42 Anytime an instruction or directive requires a numerical argument, an expression can be used. Supported operations inside expressions include addition and subtraction. The location counter $ is also made available. Expressions may contain symbols, but must resolve within two passes of the assembler, and if used for directive arguments, must resolve in a single pass. All expressions must evaluate to a positive number.
; Example with expression resolution in one pass.
;***********************************************************
foo equ 10
mvi A, foo - 04
;***********************************************************
; Assembles to the following:
Address Instruction Hex Code
------------------------------------------------------------
0x0000 mvi A, FOO - 04 0x3E
0x0001 0x0C
; Example with expression resolution in two passes.
;***********************************************************
mvi A, foo + 04
foo equ 30
;***********************************************************
; Assembles to the following:
Address Instruction Hex Code
------------------------------------------------------------
0x0000 mvi A, FOO + 04 0x3E
0x0001 0x34; Example with expression resolution in two passes, and $
;***********************************************************
mvi A, 55
jmp $ + foo
foo equ 05
db $, $ + 01, $ + foo
ds 02
hlt
;***********************************************************
; Assembles to the following:
Address Instruction Hex Code
------------------------------------------------------------
0x0000 mvi A, 55 0x3E
0x0001 0x55
0x0002 jmp $ + FOO 0xC3
0x0003 0x07
0x0004 0x00
0x0005 db 0x05
0x0006 db 0x07
0x0007 db 0x0C
0x000A hlt 0x76