I have created a detailed specification of the story files used by the original adventures by Scott Adams (and others), one which I hope would be useful to anybody wanting to write an interpreter for these games from scratch (as I did).
This is not meant as criticism, but although you mention the TI99/4A format, I think it might be worth pointing out that there are also plenty of UK cassette releases that use a slightly different binary format (created by Brian Howarth for his Mysterious Adventures, I think.)
By the way, Questprobe featuring The Hulk uses opcode 90 to draw fullscreen images.
EDIT: It might also be noted that the US releases for Apple II, Atari and Commodore 64 used their own binary format, usually credited to Mak Jukovic Jukić. This is closer to the original ASCII format than Brian Howarth’s, though.
EDIT 2: I would perhaps add to section 12.8, The Lamp Timer, that some games (at least the Mysterious Adventures) do not, in fact, replace the lamp item with its turned-off version, so if the interpreter does not handle this, the result will be a second lamp appearing while the player is still holding the lit lamp.
You probably mean Mak Jukić. He definitely wrote the drivers for the Apple II and C64 platforms, as well as the BBC Micro in the UK. I’m unsure about the 8-bit Ataris, but he’s at least credited in the Questprobe series, so probably that too.
Credits are not too reliable, though, especially where famous authors were involved; today we know that Scott Adams did not write either Pyramid of Doom or Golden Voyage, even if credited with these. Their authors were Alvin Files and William Demas respectively, who independently had reverse-engineered the game format and were cheeky enough to build their own games based on it and submit them to Adventure International for publication. Or Brian Howarth, who was credited with Seas of Blood but did not even go near it (it was Mike Woodroffe instead).
Thanks! I was copying from the readme of beeb2sf.zip, but I definitely should have googled the name. If you are reading this, Mak, sorry for mangling your name!