As a computer user/programmer for the past 20 years, I’ve always had one ambition: to build a real working computer from components. No, not a PC (which anyone can do), but a computer from the ground up.
My inspiration comes from various sources, including using a 6502-based education board at college and being amazed at the general simplicity of the thing, and more recently from some cool things I’ve found on Youtube, including some awsome work of one Mark Sarnoff.
Features I have in mind:
- Predominately made out of 70s/80s era components, but with some modern features
- 6809 based (Z80 would be too predictable and 6502s too limiting)
- Serial port as primary means of I/O
- Bank switching to make use of “massive” SRAM chips
- General I/O ports for interfacing with ordinary TTL logic
- Sound (perhaps using a SID, if I can stump up the cash, or some other synth
Software wise, I’d be happy just getting a basic monitor working first. All written by myself in 6809 asm. None of this Linux stuff anywhere.
The first step is to make a parallel EEPROM programmer. Whilst I could go and buy one, they are 1. expensive, 2. usually need Windows, 3. buying one is just too *easy*.
This is where the AVR micorocontroller comes in. This will be described in the next post…