heretyk wrote on 2024-10-19, 13:21:

What happens when -5V is not provided? Card remains silent?

"Low / No Audio"
ISA Cards & Devices Requiring -5V

Grzyb wrote on 2024-10-19, 11:50:

Yes, but: 1. make sure the power supply provides -5 Volt 2. be aware that early SB software may access the OPL2 without proper d […]
Show full quote

heretyk wrote on 2024-10-19, 10:42:

Is it possible to run this card on a newer machine? The oldest PC I have is a Pentium II.

Yes, but:
1. make sure the power supply provides -5 Volt
2. be aware that early SB software may access the OPL2 without proper delays, which makes it fail on fast CPUs - later software should be OK, AFAIR no such problems with Windows 98 SE

This. DOS games that run smoothly on an 808x or 80286 PC may be from a time when the delays were very short.

AdLib increased the numbers of recommended delays once in a while in its documents, in order to keep up with newer CPUs.

So it's likely that such DOS games may fail to have OPL2 support on a Pentium 1 already.

There was the "Runtime Error 200" bug, for example, a popular timing bug of Turbo Pascal 7 runtime. It occured on faster Pentiums (somewhere between Pentium 120 to 233).
https://www.st-andrews.ac.uk/~bds2/ltsn/tpbug.htm

Anyway, if an old DOS game was properly written, if it measured PC speed during start-up and then would set up the delays accordingly, then yes, then the timing was no issue and an OPL2 could work.
Unfortunatelly, PC programmers rarely were so thoughtful. They programmed games for the hardware that was available at the time, rather.

So it really depends. The OPL3 also had a timing issue, by the way. At one point, it would need delays, too. But it wasn't a thing in the Pre-Pentium II days so no game uses delays especially for OPL3.
If they do use delays, then because the code was derived from existing OPL2 (YM3812) code of the day.

OPL3 (YMF-262) compatible chips and later OPL3 cores (OPL3-L aka YMF289, YMF278 aka OPL4, YMF7xx , YMF825, ESS ESFM, Creative CQM, Crystal FM etc) do not require delays. Not by today's computer standard.