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

CPU

.cpu Z80

Scopes and Local Labels

Labels with a double colon begin a scope. All labels that begin with a "_" have the scope label automatically pre-pended. This allows you to reuse common labels in different places.

For instance, "_here" below is really "DrawSprite_here" in the first scope and "ClearSprite_here" in the second.

The scope prefix remains in effect until you change it with another double-colon label.

DrawSprite::
    LDB  #20
_here:
    DECB
    BNE   _here

ClearSprite::
    LDB   #20
_here:
    DECB
    BNE   _here
    ```

## Key/Value Constants

Values must be numeric.

.CONST_A = 0x20 .CONST_B = (35 + CONST_A) * 4


## 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

topherCantrell/OpcodeTools