[WIP] running ezbasic with Ruby2600's 6507 CPU emulator

ezbasic.rb

#!/usr/bin/env ruby
require 'ruby2600'

rom_file = "/Users/chester/Downloads/ehbasic.bin"
rom_addr = 0xC000

# Initialize a CPU with 64K of memory
cpu = Ruby2600::CPU.new
memory = Array.new(64*1024) { 0 }
cpu.memory = memory

# Load the ROM file into memory
rom_contents = File.open(rom_file, "rb") { |f| f.read }.unpack('C*')
cpu.memory[rom_addr..rom_addr + rom_contents.size - 1] = rom_contents

# Point the input and output vectors to a RET instruction in the ROM
memory[0x0205] = 0x02
memory[0x0206] = 0xC1
memory[0x0207] = 0x02
memory[0x0208] = 0xC1

# Run!
cpu.pc = rom_addr
while true do
  cpu.step
  # Output the accumulator as a character if we jumped into the output vector
  putc cpu.a.chr if cpu.pc == 0xE0ED
  # TODO find which key is being currently pressed if we jump into the input vector
end