opcodetools 1.0

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

Opcode Tools

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

.W 0x01,0x1234

Example Input

; Example assembly input

.include hardware.asm

._CPU = Z80
.CONST_A = 0x20

0x8000:
Start:

   LD  A,0x23     ; A constant
   LD  B,(0x10)
   LD  H,(DataA)
   LD  E,CONST_A
   JP  Start

DataA:
. 0x10,0x20,0x30

DataB:
. 0x20