Hi Tim: My dad and I put together a ZX81 back around '78. I wish I had kept it. I think this was post-Apple-][, but dad was frugal. It had 8k ROM, 1k RAM, and a 16k expansion cartridge. It cost about $50, but you had to supply a cassete recorder (storage) and a B&W TV w/ an adapater. Loads of fun. Wrote some of my first BASIC on it, so long ago.