I'll see your SoundBlaster PCI (or Soundblaster Awe 64?), and raise you a SoundBlaster ISA, which had its default IRQ set to 7. As everyone knows (now-a-days, anyway), your parallel port is set to 7. I believe the SB documentation recommended to change it to 5, and just run the setup/install/config for each app to point it to that location. Trouble, to be sure, but better than no POST what-so-ever. Why not change the default printer IRQ? In that day and age, most stuff was hardcoded to 7, with nary a way to change it. Printer usage on PC was (and ever shall be) a dark art of the lowest order. Has anyone ever met a print driver programmer? Anyone who has worked on the spooler in Windows? Perhaps a long time ago. I suspect these days they've been assimilated into/replaced with AI (or at least a near sentient collection of macros).
There was also a SB16 SCSI that could drive one's SCSI CD-ROM (50-pin) and provide one's SB sound needs, all on one card - assuming one terminated that chain properly and set one's SCSI IDs correctly. It doesn't help if one sets the drive ID to 7 - that's the SCSI Adapter's ID (by convention). Too bad if one was running an IDE hard drive with said CD-ROM, some game copy protection schemes would flip out and refuse to work at all.