opcodetools 1.1

Assemblers/Disassemblers for retro processors (Z80, 6502, 6809, etc)

Opcode Tools

Known CPUs

• 6502
• 6803
• 6809
• 8052
• DVG (Atari vector generator used in OmegaRace, Asteroids, etc)
• Z80
• Z80GB (Z80 variant used in the Nintendo GameBoy)

Disassembler

py -m opcodetools.dasm Z80 0 "test1.bin+test2.bin"

• CPU
• Origin
• One or more files that make up the binary

Assembler

py -m opcodetools.asm hello.asm

See the Example Input below.

The assembler recognizes four different kinds of text lines:

• A blank line (ignored)
• A label: a single word/number ending with a ":"
• A directive: a line beginning with a "."
• Everything else is a line of assembly opcodes

Comments

  LD  A,5  ; Five rows per object

Everything after a ";" on a line is ignored as a comment. Lines that begin with a ";" are seen as blank lines (ignored).

Includes

.include hardware.asm

Key/Value Constants

._CPU = Z80
.CONST_A = 0x20

KEY = VALUE pairs. Keys that begin with "_" are meant for the assembler.

Data Definition

Bytes

. 0x01,2,3,4,0x05

Words

.word 0x01,0x1234

Example Input

; Example assembly input

.include hardware.asm

._CPU = Z80
.CONST_A = 0x20

0x8000:
Start:

   LD  A,0x23     ; constant
   LD  A,(0x10)   ; memory location
   LD  HL,(DataB) ; memory location
   LD  HL,DataA   ; constant
   LD  E,CONST_A  ; constant
   JP  Start

DataA:
. 0x10,0x20,0x30

DataB:
. 0x40,0x50