I had absolutely no idea re: the LinnDrum being a PC. That's really cool. I've never seen one in the flesh, but now I'm wondering if anybody has done conservation of the firmware. It would be a lot of fun to look at the code.
8086 didn't according to https://retrocomputing.stackexchange.com/questions/11327/wha..., but V30 was more like an 80186 which did trap, but then 8080 emulation mode might have worked differently again.
Also I don't recall how I worked out that the extended Z80 instructions were causing the problem. Debugging was a lot more complicated in those days, although programs were also much smaller.
https://www.ceibo.com/eng/datasheets/NEC-V20-V30-Users-Manua...
according to MAME V40 has it as standard exception 6? https://github.com/lesbird/MAME4apple-037b5/blob/master/MAME... Then again https://forum.vcfed.org/index.php?threads/nec-v20-and-cp-m.7... says no.
https://octopart.com/upd70136al-12-nec-10428216
Did you mean during development? LM-1 does not look like a PC, though I think I do see the NEC CPU in these screemshots: https://www.matrixsynth.com/2014/06/vintage-linndrum-lm-1-sn... - of course there's more to a vintage PC than an 8086.
https://www.elektronauts.com/uploads/default/original/3X/6/8...
https://www.elektronauts.com/t/the-seminal-groovebox-linn-90...
https://www.vintage-radio.net/forum/showthread.php?t=87739
http://studiorepair.com/gallery/Linn/9000/index.html
LM-1 and LM-2 were Z-80 based. Damn, cant edit my first post :( Thank you for correction.
V33 was used in PC-98 DO+, and in SOC form (NEC V53) in legendary Akai MPC3000, probably because Roger Linn's original LM-1 and LinnDrum were also full x86 PCs with custom cards.
Sadly I cant find any place that sells V33/V53, maybe could be sourced in Japan.