I went down an “Infocom sound” rabbit hole…
I’ve already shared most of my findings with the one other person I know who is interested in creating Z-machine games with sound, but this might be helpful to someone else out there, too.
Concerning the bit which is set in the header to enable sound in the terp…
Short version:
- Only Amiga (and Atari?) releases of Lurking Horror and Sherlock included sound (as far as I can tell)
- None of those story files from those Amiga disks have anything set in “Flags 1” (MODE from
ZVERSION) - Lurking Horror (Amiga) r219 and r221 (v3 story files) both have bit 4 set in
FLAGS(“Flags 2”) - Sherlock (Amiga) (v5 story file) has bit 7 set in
FLAGS(“Flags 2”). - None of the DOS versions of either game had sound functionality. So no bit 4 in Lurking Horror, and no bit 7 in Sherlock. (Nothing at all ever seems to be set in MODE on DOS, either.)
My notes (including header info from unz, source code, etc): zmachine sound (notes).md · GitHub
Also, here are my notes concerning SND files for DOS: The Infocom SND Format in 2025.md · GitHub
WARNING: Somewhere in those notes concerning the SND format, there is code to convert a RAW audio file to SND, and it was generated by Google Gemini. (Cue dramatic music!) I had to test and tweak/change things at least a hundred times to get that working. I do not know how to code in C (yet), and I got tired of opening RAW files in HxD to add the headers manually to convert to SND files during testing; so, I had Gemini whip something up. I also used Gemini and Claude to learn some fundamentals I’d never had a chance to learn, but most of the help I got came from actual people: asking numerous questions here and on Discord, reading the docs, scouring through old code on ifarchive, etc. I thank those kind people wholeheartedly. Any mistakes in any of this came from me, not them. I would like to correct any mistakes that are found, too; so, be sure to point them out if/when anyone finds any. =)
Also also, I did not get sound working in Frotz 2.55 (or the current code from the repo) on DOS yet. I decided to learn as much as I could about all of this before giving it another shot. I shall report back here if I get anywhere with that, though.