I may have caught the 'write an emulator' bug. This is just a place holder for now. The plan is to write a simple emulator of an Intel 4004. I'll add some memory mapped io for a display. Probably character based at this point.
Testing the emulator will require ROM images which seem fairly scarce. I'll make some ROMs using the assembler located here.
I wasn't intending to emulate the individual RAM chips though I may end up doing this due to the close relationship of some of the instructions to the hardware.
The 4004 is a 4 bit CPU. Characters are 4 bit, words are 8 bit, addresses are 12 bit.
| Type | Bits | Rust Type |
|---|---|---|
| char | 4 | u8 |
| word | 8 | u8 |
| address | 12 | u16 |