__         ______ _______
    |__| ______/  __  \\   _  \
    |  |/  ___/>      </  /_\  \
    |  |\___ \/   --   \  \_/   \
/\__|  /____  >______  /\_____  /
\______|    \/       \/       \/

js80 is a library and an assembler for z80 cpu.

Installation

npm install js80 -g

Command line

js80asm help:

  Usage: js80asm [options] <file ...>

  Options:

    -h, --help                     output usage information
    -V, --version                  output the version number
    -o, --output <file>            create binary compiled file (default a.out)
    -I, --include <dir1:dir2:...>  add directories into the search list
    -s, --sym <file>               create sym file

Examples:

js80asm test.asm

js80asm test2.asm -o test2.rom -s test2.sym

js80asm test3.asm -I include:../include2

JS80 class

Creation

var JS80 = require('js80');
var js80 = new JS80();

Class functions

• asm js80.asm(code) ··Compile assembler code.
• defineLabel js80.defineLabel(label, value) ·· Defines a new label.
• secondPass js80.secondPass() ··Execute the second pass. The compiler evaluates the expressions because labels can be declared later.
• buildImage js80.buildImage() ··Returns an array of bytes with the compiled code.
• saveImage js80.saveImage(fileName) ··Save compiled code to a file.
• saveSymbols js80.saveSymbols(fileName) ··Save symbols to a file (useful for debugging).

Example:

var JS80 = require('js80');
var js80 = new JS80();
js80.asm('xor a');
js80.secondPass();
js80.saveImage('a.out');

Assembler

Expressions

Examples

run: ld b,100
.1:  ld a,(hl)
     inc a
     ld (hl),a
     inc hl
     djnz .1
     ret
unuseful:
     jr run.1

      module mod1
util: xor a
      ret
      endmodule

      // no module
main: call mod1.util ; calling a module label
      ret

macro noargs
    xor a
endmacro

macro withargs i, j
    ld a,i+j
endmacro

macro withdefaults i, j:1, k:2
    ld a,i+j+k
endmacro

macro varargs i, 1..*
    repeat @0
        ld a,i+@1
        rotate 1
    endrepeat
endmacro

Assembler modules

• bios.asm: MSX 2 Bios functions and variables (bios.WRTVRM, bios.H_KEYI, ...)
• rom16k.asm: MSX 16kb rom setup (start label is the entry point)
• rom32k.asm: MSX 32kb rom setup (start label is the entry point)
• megarom.asm: MSX megarom setup (start label is the entry point)
• extensions.asm: Misc utility macros
• math.asm: Misc math funcs
• debug.asm: OpenMSX debug output

Opcodes