the software i'm using by the way is PC-BASIC which i found out about yesterday
it's a modern recreation of GW-BASIC, BASICA et al, simulating many video modes including Hercules and even Tandy 3-channel sound
https://robhagemans.github.io/pcbasic/
the book targets C64, TRS-80, Spectrum and Apple, so we'll find out what bugs arise and need to be fixed only once i'm done typing and try to run it
oh nevermind!
went to check on a dumped BBC copy of the game (it has a fancy title screen, perhaps usborne published it as a disk at some point, or a superfan made a very fancy version?) and the behaviour i thought was a parser bug is there just as on my conversion
well, time to test play it through then :)
after fixing a couple more typos, it seems the game is playable
but i'm rubbish at it 😅
i'll take a break for today, i've taken down notes on what i found interesting about this experience to write a blog post on later