I can tell you from reading the code in the 90s, no LLM will save you. It’s well written, but it’s not structured like modern programs. IIRC he invented his own trampoline system using goto that will leave you scratching your head for days, just trying to figure out how it works. An LLM might be able to guess, but it def isn’t going to one-shot it and that means you will need to be able to understand it as well.
I do think it is possible with the advent of Claude Agent to transpile the code. First I would refactor the trampoline system to be functional and unit test everything. Then I would use those tests to validate the transpilation. It's something that I would consider doing for a Wall Street Raider 2 to overhaul the engine and deliver massive improvements to the engine itself. I do want to do this to a certain extent to implement automated e2e testing. But I don't mind BASIC at all, prefer it actually, I just want automated testing set up. But a lot of this is beyond the scope of my goals for Early Access release.