awesome / 6809js

Motorola 6809 emulator in JavaScript

6809js

An JavaScript emulation of Motorola 6809 CPU

Used in all emulations at ASM80 online IDE

You can use 6809js also as Node.js or AMD module.

Usage

(a.k.a. The API)

• window.CPU6809 - main object (instantiated at the start - it shall change)
• CPU6809.init(memoryTo,memoryAt,ticker) - Initializes the whole system. All parameters are callback functions for port / memory access:
  • memoryTo(addr,value) - store byte to given address
  • memoryAt(addr) - read byte from given address
  • ticker(T) - unused now. For future use
• CPU6809.T() - returns clock ticks count from last init (or reset)
• CPU6809.reset() - does a CPU reset
• CPU6809.set(register, value) - sets internal register (named PC, SP, U, A, B, X, Y, DP, FLAGS) to a given value (SP means S, it's for compatibility)
• CPU6809.status() - Returns a object {pc, sp, u, a, b, x, y, dp, flags} with actual state of internal registers
• CPU6809.steps(N) - Execute instructions as real CPU, which takes "no less than N" clock ticks.

Disassembler:

NOT YET READY

Tests

6809js is slightly tested with qUnit - just a basic functionality at this moment

Roadmap

• full interrupts support
• full CWAI emulation
• HD6309 extended mode