i40xx-asm

Assembly for Intel 4004/4040 architecture

Installation

Install globally:

npm install -g i40xx-asm

Usage

Compiles program.i4004 into ROM image and store it into program.bin

i40xx-asm program.i4004 program.bin 

You can omit output file name, in that case assembler would replace extension of input file name to .bin

Assembly Syntax

Comments started with #:

# comment

Labels could be used:

label:
  NOP
label2: DCL

Each instruction should be on separate line and can have 0, 1, or 2 operands:

  instruction
  instruction operand
  instruction operand1, operand2

Operand could be one of kind:

• 4-bit index register, format is rrX, where X is [1..16]: LD rr10
• 8-bit index register pair, format is rX, where X is [1..8]: FIN r3
• immediate value, either hex or decimal: LDM 0xF / FIM r2, 200
• ROM address, format is XX:YYY, where XX is page number (in decimal form) and YYY is offset inside page: JUN 5:0xDD
• label name: ISZ rr5, do_loop
• condition (for JCN instruction), combination of symbols n (invert condition), z (if zero), t (if test signal is 0), c (if carry): JCN nz, non_zero

Sample program (iterate through all RAM banks, RAM chips and their registers and fill RAM words by specific value):

  FIM r0, 0x80
loop_bank:
  // select bank
  LD rr1
  DCL
  // iterate through reg number
  FIM r1, 0x00
loop_reg:
  LDM 0
  XCH rr3
  SRC r1
  LD rr1
  WRM // write rr1 to [#rr1, #rr2, M0]
  WR0 // write rr1 to [#rr1, #rr2, S0]
  INC rr3
  SRC r1
  LD rr2
  WRM // write rr2 to [#rr1, #rr2, M1]
  WR1 // write rr2 to [#rr1, #rr2, S1]
  ISZ rr2, loop_reg
  INC rr1
  ISZ rr0, loop_bank
halt:
  JUN halt

Module/Programmatic Usage

i40xx-asm can be required as a module:

const { compile } = require('i40xx-asm');

const { errors, blocks } = compile('nop');
if (Array.isArray(errors) && errors.length) {
  console.log(errors);
  process.exit(1);
}

console.log(`First byte of first block is ${blocks[0].bytecode[0]}`);