This is my modified build of Ben Eater’s 8-bit computer project - which is an incredible introduction to digital electronics and computer architecture! I won’t explain the background to the project in detail here, so do check out Ben’s awesome YouTube series.
In brief, the idea is to use basic 7400-series logic chips wired together on breadboards to build the simplest possible programmable computer from scratch.
The architecture and layout of my build follows Ben’s fairly closely, with a few enhancements:
- 74HC series chips
- 16-bit address bus, to enable addressing of 32KB SRAM
- 16-bit memory address register
- 16-bit instruction register, to give an 8-bit instruction opcode and 8-bit operand
- 2 x 16-bit general purpose registers C and D, although arithmetic remains 8-bit
- 8-bit segment register to extend the 8-bit program counter (allowing execution beyond the bottom 256-byte memory segment)
- Arduino Nano to bootstrap the SRAM, and allow direct SRAM write-only via USB
I've also written an assembler and emulator, to ease development.
See docs/Index.md.