It is a speed-related issue. I can reproduce the error when running DOSBox at the default "cycles" setting of 3000. When I set the "cycles" setting to 320 before running the game, no error is produced.

I also notice that a common download of this game uses BASIC.EXE from Tandy DOS, which will have no sound at all on a non-Tandy computer, and which most certainly is not the originally-intended interpreter version. Using non-Tandy GWBASIC.EXE v3.23 also solves the illegal function call issue.

Jorpho wrote on 2021-02-17, 05:18:

...a bug that is trivial to replicate via the Archive.org emulator:

That's what happens when you use an automated script to slap the default DOSBox settings onto every game regardless of what it actually requires, and then pretend you're doing "preservation". 🤷

Speaking of weirdo BASIC errors, there's still a prize out on the mysterious "Error 241" check in IBM's Arithmetic Games...

Thanks, I'm glad that little riddle is solved.

VileR wrote on 2021-02-18, 15:22:

That's what happens when you use an automated script to slap the default DOSBox settings onto every game regardless of what it actually requires, and then pretend you're doing "preservation". 🤷

Well, they do call it "experimental and very new technology" in the rather poorly-written FAQ. I would try to E-mail Mr. Scott but his inbox is probably an absolute horror show.