Hey all, I'm new to the emulator writing game. I just decided a few days ago to write a 6502 emulator in Zig. Eventually I may work up to emulating a whole //e. One thing that I've been looking for that I haven't found so far is the availability of unit tests for each individual 6502 opcode in a language neutral format. I've found plenty of unit tests embedded in the source code of emulators that have published their source code and I've found quite a few large test suites that will test everything on a 6502 all in one binary.

The unit tests embedded into the source code of other emulators are useful, except that it's very tedious and error prone to try and understand the source project and then convert those tests to your system. And until your emulator is nearly finished the large test suites are not very useful.

What I'm looking for would be a set of YAML or JSON files that have the instructions for initializing the emulated CPU & memory with a certain state (flags, registers, data). Then the CPU would be stepped to run a single instruction. Lastly the state of the system would be compared to what's listed in the test file to make sure that it matches.

I think that would be invaluable for anyone developing a 6502 emulator. If anything like that exists, I'd love to hear about it.

I do not know of any thing that would be a definition in JSON or otherwise; unit tests are usually very specific to whatever code base your developing in.

That being said, I know there are some various test programs that run on the 6502 itself to verify that it is working.

The Klaus tests are one such set:
https://github.com/Klaus2m5/6502_65C02_functional_tests

Depending on how accurate you want to go, different variations of the 6502 will have some slightly different side effects in some cases. Rockwell NMOS vs. WDC CMOS vs. Roch 2C02 for example.

The work of forum member cjs comes to mind ... perhaps close to what you seek?

search.php?st=0&sk=t&sd=d&sr=posts&keywords=+unit+test&author_id=2898

(I hope I'm not wasting your time ... I don't have the tiniest clue what a YAML or a JSON is, and my biological hard drive is in desperate need of a defrag ... ]

_________________
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Here is another possibility:
http://forum.6502.org/viewtopic.php?f=8&t=8119&p=108636&hilit=json#p108636

Aha! That led me to this GitHub project:

https://github.com/SingleStepTests/65x02/tree/main/6502

That's perfect!