First post, by randomtestsubject
This is a bit of an unusual request I'm sure, but does anyone here know of any PCI sound cards that can be initialized to use IRQ 4 in pure DOS?
For those curious as to why anyone on Earth would want that, I have a pure MS-DOS 6.22 PC (Cyrix III 700mhz on an ECS P6BAT-A+ motherboard) that I have set up for the sole purpose of running Voyetra's old Sequencer Plus Gold on. This DOS-only and MIDI-only sequencer is capable of driving 8 MIDI output ports given the right combination of interfaces, using its own specific drivers. There are two driver types: a primary "VAPI" driver which supports a broad range of now-vintage MIDI interfaces, must be loaded (but can only be loaded once), and secondary "SAPI" drivers, which only support Voyetra interfaces or MPU-401 compatible cards, but can be loaded multiple times, once for each additional interface. Each SAPI MPU driver that is loaded adds a single 16 channel MIDI Out per card.
Currently I have 5 MIDI Outs, based on the following sound card/midi interface configuration:
1. A Music Quest 2Port/SE parallel port interface using the motherboard's LPT1 on IRQ 7. This provides MIDI Outs 1 and 2.
2. A Music Quest MQX-32M on IRQ 2/9. This is a two output card but the SAPI MPU driver sees it as one. So that's MIDI Out 3.
3. A Yamaha Audician 32 ISA PNP sound card on IRQ 3, for MIDI Out 4. (This and the MQX occupy the motherboard's only two ISA slots.)
4. A CMI8738 on the motherboard, which grabs hold of IRQ 5 with no apparent way to change it, provides MIDI Out 5.
Amazingly, this all works, and I'm actually pretty chuffed to have this many ports. I hope that one day I can acquire a Voyetra V-24s, which in place of the MQX-32M would give me the full 8 ports, but these surface so rarely that I'm not holding my breath. In the meantime though, I do wonder if I might be able to achieve 6, given that I still have a free PCI slot and one free IRQ from the 3,4,5,7 and 9 that SAPI scans. (Both COM ports are disabled in the BIOS, freeing IRQs 3 and 4.)
The one card I have tried to add so far was an Ensoniq AudioPCI, which was unsuccessful. Even though the card initializes correctly, SAPI cannot see its MPU-401 port. Perhaps there is something particular about how this card emulates the port, but it leads me to believe that no Creative or Ensoniq cards are likely to work.
So that's the back story. In the end I'm okay with 5 ports, but the possibility of 6 provides an interesting tech challenge if nothing else. I'm dreaming that there is some PCI sound card out there that works in pure DOS, can be initialized to IRQ 4, is cheap because it does something this use-case doesn't require very poorly, but still provides a reliable MPU-401 compatible port in UART mode.
Does such a card exist, to anyone's knowledge? Thoughts and ideas welcome.