The one I know of by heart is Stellar 7. Good idea to start drafting a list! The total list might turn out not to be all that long and perhaps those games could be fan-patched to support different settings or even to automatically parse the BLASTER environment variable. 😀

By the way, I never understood why Creative didn't standardize on IRQ 5 in the first place, since IRQ 7 was already in use by the LPT1 printer port on most DOS PCs, but IRQ 5 was usually free. 😒 I guess sharing IRQ 7 between the printer port and the sound card never posed a problem in DOS games and didn't become an issue until people started using Windows and other multitasking environments, which could lead to both devices being accessed simultaneously. But couldn't Creative Labs have foreseen this development when they designed the first Sound Blaster card? Why did they default on IRQ 7? I'm curious about the story behind that decision.

Links?

digger wrote:

By the way, I never understood why Creative didn't standardize on IRQ 5 in the first place, since IRQ 7 was already in use by
the LPT1 printer port on most DOS PCs, but IRQ 5 was usually free. 😒 .

IRQ5 was not free on the PC/XT platform. It was used by MFM/RLL hard disk controllers there. 🙁
IRQ7, on the other hand, was more or less free. It rarely happened that a line printer was in use while a game was running.

I would be interested in this as well. I've heard Gods requires IRQ 7, but have never checked it out.

Conversely - I wonder if there are any newer games that require IRQ 5.

I'm in. The time between when the Sound Blaster was released up until the point where IRQ 5 was the standard default was pretty short.

Tenorman wrote:

I've heard Gods requires IRQ 7, but have never checked it out.

Haven't had any issues with my copy using IRQ 5. 😀

Space Quest 3 - however, this is only if you want to hear Roger speaking at the intro and when he jumps out of the escape pod.
I think that this can be edited somewhere in one of the game files to use IRQ5.

I always set up IRQ7 and this has led to some headaches in the past, so this would interest me greatly 😀.

Does Prince of Persia work with IRQ 5?

GODS has missing samples if the SB-IRQ is not 7.

jesolo wrote:

Space Quest 3 - however, this is only if you want to hear Roger speaking at the intro and when he jumps out of the escape pod.
I think that this can be edited somewhere in one of the game files to use IRQ5.

I thought itÄs on tandy-dac only. Good to know.

Jo22 wrote:

digger wrote:

By the way, I never understood why Creative didn't standardize on IRQ 5 in the first place, since IRQ 7 was already in use by
the LPT1 printer port on most DOS PCs, but IRQ 5 was usually free. 😒 .

IRQ5 was not free on the PC/XT platform. It was used by MFM/RLL hard disk controllers there. 🙁
IRQ7, on the other hand, was more or less free. It rarely happened that a line printer was in use while a game was running.

Ah, got it. That actually makes sense, yes. I remember when I built my first PC in my teens, a 486DLC. 😀 Either I had run out of money for an IDE hard drive once I had bought the other components from my hard-earned paper route money, or I had one on order, I don't quite remember. Anyway, in the meantime I installed an old dodgy Miniscribe RLL drive in it, so I could play games that required a hard drive. To my disappointment, the RLL drive and my Sound Galaxy card refused to play nice together. Strangely enough, I do remember trying to get the sound card to work with other hardware settings while having the RLL drive installed, but I couldn't get it to work. I could have sworn I had tried IRQs other than 5 as well. To no avail. I remember the frustration of only being able to play Dune II with internal speaker sound, even though I had a perfectly good sound card. I would also occasionally take out the hard drive, so I could play Space Quest III with Sound Blaster sound and using floppies, on a 386/486 system! 🤣 Soon after that I got a 250MB Conner IDE drive, which solved that problem. Ah, memories. 😀 By the way, that wasn't the end of my sound card troubles with that machine, but that's a different story.

CkRtech wrote:

I'm in. The time between when the Sound Blaster was released up until the point where IRQ 5 was the standard default was pretty short.

While we're at it, we should also make a list of games that supported Sound Blaster only on DMA 1. I remember the conventional wisdom being that using DMA 3 instead of DMA 1 would cause even more games not to work than using a different IRQ. But perhaps that's not true, or at least not to such a great extent as I had understood back in the day? Were there really that many games out there that allowed the selection of a different IRQ, but not a different DMA channel?

On my old DOS machines, I set the soundcards to use IRQ5 because IRQ7 was already used for the parallel port. I do recall having to configure a lot of games away from the default IRQ7 for sound, even with the BLASTER environment variable set. I never understood why the default sound IRQ was 7 instead of 5. I don't have much experience with XT machines, but it seems like those should have used IRQ2 for the hard disk instead of IRQ5. In the original IBM PC, both the IBM Monochrome Display and Parallel Printer Adapter and the Parallel Printer Adapter (used with the Color Graphics Adapter) were hardwired to IRQ7.

I had always thought that the first parallel port (LPT1) should be on IRQ7, and a second port (LPT2) on IRQ5, if you had two printers. So normally, IRQ5 was free. IRQs, I/O addresses, DMA channels -- I'm happy these all became autoconfig with the PCI bus. And with DOSbox, you can put the emulated soundcard on your choice of IRQ for game compatibility (can't always do that with real hardware).

David_OSU wrote:

On my old DOS machines, I set the soundcards to use IRQ5 because IRQ7 was already used for the parallel port. I do recall having to configure a lot of games away from the default IRQ7 for sound, even with the BLASTER environment variable set. I never understood why the default sound IRQ was 7 instead of 5. I don't have much experience with XT machines, but it seems like those should have used IRQ2 for the hard disk instead of IRQ5. In the original IBM PC, both the IBM Monochrome Display and Parallel Printer Adapter and the Parallel Printer Adapter (used with the Color Graphics Adapter) were hardwired to IRQ7.

I had always thought that the first parallel port (LPT1) should be on IRQ7, and a second port (LPT2) on IRQ5, if you had two printers. So normally, IRQ5 was free. IRQs, I/O addresses, DMA channels -- I'm happy these all became autoconfig with the PCI bus. And with DOSbox, you can put the emulated soundcard on your choice of IRQ for game compatibility (can't always do that with real hardware).

As Jo22 pointed out, IRQ 5 would often be taken up by MFM/RLL hard disk controllers on PC/XT systems and since printers and sound cards were never used at the same time or within the same application in the DOS era, IRQ 7 was chosen and would work without problems. As for IRQ 2, I believe the 80286-based PC/AT was already released by the time that the first Sound Blaster come out. 286 systems introduced a secondary IRQ controller that was cascaded through IRQ 2 on the primary IRQ controller, thus making IRQ 2 unavailable to add-on cards.

The default use of IRQ 7 by Sound Blaster cards didn't become an issue until the Windows 3.1 era, which introduced multimedia in a multitasking environment. So by that point, you could be listening to a WAV file being streamed from your hard drive to your sound card while printing out a Word document to a printer on the parallel port, which required the hard drive controller, sound card and parallel port to each have their own IRQ channel. This would be the case at least until the advent of IRQ sharing, which I believe wasn't an available feature until much later. But anyone here more knowledgeable than I, feel free to correct me. 😀

F2bnp wrote:

Does Prince of Persia work with IRQ 5?

Yes.

David_OSU wrote:

On my old DOS machines, I set the soundcards to use IRQ5 because IRQ7 was already used for the parallel port.

Hi, digger explained it very well I think. 😀
I got my information from the web, as well as from my own PC/XT clone, a Nixdorf 8810 M85 (specs of another user's page).
Source: http://philipstorr.id.au/pcbook/book2/irq.htm

I've added a screen shot below. I didn't change any of the IRQs when I got it. The machine was first built in ~85.
The MFM/RLL drive is an ancient 5,25" model with 20MB, along with an equally old controller card.
So unless the owner had made some changes, it had always been configured for IRQ5.

David_OSU wrote:

I had always thought that the first parallel port (LPT1) should be on IRQ7, and a second port (LPT2) on IRQ5, if you had two printers.
So normally, IRQ5 was free.

Well, yes and no. While, the IRQ for LPT1 indeed often was IRQ7, LPT2 wasn't always on IRQ5.
In my PC clone, both are on IRQ7. That's because both the on-board LPT as well as the LPT on my Hercules clone are hard-wired.
That's why I'm afraid that in the 1980s, not all expansion cards containing an LPT port were configureable in this respect.
Amyway, as digger pointed out, IRQ sharing at least was no issue in DOS. DOS didn't do port probing as Win9x did.
So I believe that -unless you had something like DESQView with a printer spooling running-, having both SB and LPT on IRQ7
caused no real harm. When PC/AT machines became ubiquitous, Creative switched to IRQ5. Simply because it was safely free now.
I believe the change happened with the SB Pro 2, but I'm not 100% certain. It was roughly after the SB 2.x and before SB16, though.

Edit: Quote and link added.

digger wrote:

CkRtech wrote:

I'm in. The time between when the Sound Blaster was released up until the point where IRQ 5 was the standard default was pretty short.

While we're at it, we should also make a list of games that supported Sound Blaster only on DMA 1. I remember the conventional wisdom being that using DMA 3 instead of DMA 1 would cause even more games not to work than using a different IRQ. But perhaps that's not true, or at least not to such a great extent as I had understood back in the day? Were there really that many games out there that allowed the selection of a different IRQ, but not a different DMA channel?

I remembered Halloween Harry saying something about that. I found the text in my directory for the game. Not sure if it had the same rules applied to the rename "Alien Carnage"

Halloween Harry hh-help.exe wrote:

Halloween Harry requires that the DMA channel of your SoundBlaster card be on 1.
If your DMA Channel is on any other channel, then you must change it to 1 in order to get the Halloween Harry sounds working properly.
Furthermore, the IRQ channel must be 7 or less. An IRQ higher than 7 will also cause the game to malfunction.

There is no any game that requires exactly SB IRQ 5 or 2. This story is only about 7 and only about some older games with SB / SB Pro support. A newer games with SB 16 support don't require any especial resources allocation. Therefore my scheme is:
SB Pro 220/7/1
SB 16 240/5/0/5 or 240/9/0/5 (ACPI disabled)
LPT 7/5
Nobody disturbs to put LPT to IRQ5. It will work! And SB 16 will work with IRQ9 also! And never set SB/SB16 irq more than 7. Many games require "7 or less". 9 is possible because it is the same as 2 for games.

So separate thread for DMA 1 reqs?

PARUS wrote:

Nobody disturbs to put LPT to IRQ5. It will work! And SB 16 will work with IRQ9 also! And never set SB/SB16 irq more than 7.
Many games require "7 or less". 9 is possible because it is the same as 2 for games.

That seems valid. Also, only a few programs require an IRQ for talking to the LPT (OS/2 1.x ?).
That's why dedicated, modern LPT cards (ISA) are fully configurable and allow setting the IRQ to "none".
With old style cards, it's not difficult, either. Just cut the trace going to specific pin that matches the IRQ line on the ISA edge connector. Or cut/remove the pin of the IC connecting to that pin. If someone works with caution, it's also possible to re-wire the IRQ line to another pin.
However, using IRQ5 for LPT2 *might* confuse some programs such as CheckIt! or old XT BIOSes.
In worst case, LPT1 becomes LPT2 because of this. Anyway, no real harm is done. 😀

CkRtech wrote:

So separate thread for DMA 1 reqs?

Maybe ?
Anyway, I vote for DMA0! I'd be a refreshing choice. 😈