index.js

import './style.css';

const createMemory = require('./VM/create-memory');
const CPU = require('./VM/cpu');
const instructions = require('./VM/instructions');
const MemoryMapper = require('./VM/memory-mapper');
const createScreenDevice = require('./VM/screen-device');

const IP = 0;
const ACC = 1;
const R1 = 2;
const R2 = 3;
const R3 = 4;
const R4 = 5;
const R5 = 6;
const R6 = 7;
const R7 = 8;
const R8 = 9;
const SP = 10;
const FP = 11;

const MM = new MemoryMapper();

const memory = createMemory(256 * 256);
MM.map(memory, 0, 0xffff);

//Map 0xFF bytes of the address space to an "output device" - just stdout
MM.map(createScreenDevice(), 0x3000, 0x30ff, true);

const writableBytes = new Uint8Array(memory.buffer);

const cpu = new CPU(MM);

let i = 0;

const writeChatIntoTerminal = (char, position) => {
  writableBytes[i++] = instructions.MOV_LIT_REG;
  writableBytes[i++] = 0x00;
  writableBytes[i++] = char.charCodeAt(0);
  writableBytes[i++] = R1;

  writableBytes[i++] = instructions.MOV_REG_MEM;
  writableBytes[i++] = R1;
  writableBytes[i++] = 0x30;
  writableBytes[i++] = position;
};

'Hello World!'.split('').forEach((char, index) => {
  writeChatIntoTerminal(char, index);
});

writableBytes[i++] = instructions.HLT;
cpu.run();

// // Run the Code step by step
// {
//   cpu.debug();
//   cpu.viewMemoryAt(cpu.getRegister('ip'));
//   cpu.viewMemoryAt(0xffff - 1 - 42, 44);

//   document.addEventListener('keydown', (e) => {
//     if (e.key == 'Enter') {
//       cpu.step();
//       cpu.debug();
//       cpu.viewMemoryAt(cpu.getRegister('ip'));
//       cpu.viewMemoryAt(0xffff - 1 - 42, 44);
//     }
//   });
// }