add Yamaha OPL3-SAx PnP identification. add reminder to self that even
though the OPL3-SAx emulates an SB Pro and can offer better playback
through the Windows Sound System interface at 0x530, this library will
focus on the Sound Blaster interface, and that I will start a separate
library that focuses on the WSS. Programs wishing to use both can link
to both libraries and pick the most appropriate sound card interface.
I do however plan on adding very minimal WSS I/O code to this library
for the OPL3-SAx because I might be able to read from the OPL3-SAx chip
what the emulated Sound Blaster's IRQ and DMA assignments are.
OPL3-SAx PnP reading: look for the 8-bit DMA channel marked bytecount
(usually the second one) because that one is the Sound Blaster DMA
channel.
OPL3-SAx cards (on the laptop I test) do not have a 16-bit DMA channel,
only two 8. The WSS interface probably allows 16-bit PCM, but the Sound
Blaster emulation (the interface we care about) does not offer it.
PnP devices can have Sound Blaster out to 0x280
add OPL3 resource reading. add struct members to hold WSS and OPL3SAx
control IO ports.
iop count fix