COSMAC Emulator

This is an emulator for the RCA 1802 "COSMAC" microprocessor.

Project status

I work on this from time to time, usually when I have the itch to futz with the 1802 membership card. It's useful for testing out ideas before going the hassle of loading them into the device, but it's still pretty clunky.

Usage

To load an image:

$ cargo run -- --image stack-test.bin
00000000 d=00.1 x=00:0000:f8 p=00:0000:f8 08    ldi  8
>>

For testing that involves handling external events, you can inject an event file, containing rows of time_ns,event_type[,payload], and specify the duration of each machine cycle:

$ cat events.evlog
110200,flag,ef3,0
232920,flag,ef3,1
593003,int
969022,input,io5,fb

$ cargo run -- --image event-test.bin --event-log events.evlog --cycle-time 2us
00000000 d=00.0 x=00:0000:f8 p=00:0000:f8 08    ldi  8
>>

To Do

• The CLI leaves much to be desired.
  • clap and clap-repl are just OK for interactive CLIs.
  • The commands themselves are not terribly consistent or well-documented.
• Add better hooks for testing.
  • For example, to validate that a PLL transmitter generates a correctly-timed waveform on Q.
  • Maybe write a log file of externally visible events?
• Listing/symbolic integration would be super nice.