Trouble changing IRQ settings of SB16 Vibra \ VOGONS

Trouble changing IRQ settings of SB16 Vibra

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First post, by kikendo

Posted on 2021-09-05, 16:53

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I have a Vibra SB16 that works just fine in the way I have it configured, but I noticed a lot of games want the card to be in IRQ7 instead of 5 (like Martian Memorandum) and I have been landing onto trouble trying to change this configuration

- I have tried both with the SB16 utilities (like CTCM) and UNISOUND, to no avail.
- I have changed the BIOS settings, reserving IRQ7 for ISA devices (and changing the parallel port which was at 7 originally, to IRQ 5)
- Using CTCM, it says it configures it at IRQ7, but then DIAGNOSE /S says IRQ5. Doing no args DIAGNOSE fails to test at IRQ7
- Using UNISOUND, it says it is at IRQ7, but games don't work with that setup/have no sound.

How am I suppose to be doing this? I feel like some util should be able to change the IRQ succesfully. Is there a jumper I need to set? I thought this card was PnP.

Reply 1 of 6, by Gmlb256

Posted on 2021-09-05, 18:33

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Which variant of the SB16 Vibra are you using?

Reply 2 of 6, by mkarcher

Posted on 2021-09-05, 18:38

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What you describe is supposed to work. You moved the parallel port away from IRQ7, so ISA IRQ7 should be free. Afterwards, you disallowed the BIOS to assign IRQ7 to PCI devices, so IRQ7 is available to ISA devices that are not configured to use ISA. Finally, you told CTCM or UNISOUND to configure the SB16 to IRQ7, which is free and assigned to ISA. This is exactly how it is supposed to work. You didn't mention the BLASTER variable, but I expect you also edited AUTOEXEC.BAT to have it say I7 instead of I5.

I am confused why DIAGNOSE /S reconfigures the card to IRQ5. DIAGNOSE /S is meant configure pre-PnP soundblasters, and it uses the BLASTER variable. So if BLASTER says I7, DIAGNOSE should configure pre-PnP-cards to IRQ7, not IRQ5.

Reply 3 of 6, by Gmlb256

Posted on 2021-09-05, 19:02

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mkarcher wrote on 2021-09-05, 18:38:

I am confused why DIAGNOSE /S reconfigures the card to IRQ5. DIAGNOSE /S is meant configure pre-PnP soundblasters, and it uses the BLASTER variable. So if BLASTER says I7, DIAGNOSE should configure pre-PnP-cards to IRQ7, not IRQ5.

Indeed, that doesn't make any sense to use for PnP based cards.

Reply 4 of 6, by Horun

Posted on 2021-09-05, 23:03

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Which CT model Vibra ? Did you try with BIOS set to PCI instead of ISA ? I know sounds wrong but...
Have a Awe32 CT-3990 that gave me similar issues on one specific Pentium board. Found out by trial and error that the BIOS was not truly allowing IRQ7 to be used for PnP ISA when BIOS was set for ISA.
It was a specific BIOS version issue on that board iirc. What caught my eye was on a diff board trying same Awe32 the BIOS settings were: ISA or PCI/PNP but the other board just listed ISA or PCI.
Am going way back in memory so could be wrong but if you have not tried that it could not hurt 😀

Hate posting a reply and then have to edit it because it made no sense 😁 First computer was an IBM 3270 workstation with CGA monitor. Stuff: https://archive.org/details/@horun

Reply 5 of 6, by kikendo

Posted on 2021-09-24, 15:09

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mkarcher wrote on 2021-09-05, 18:38:

I am confused why DIAGNOSE /S reconfigures the card to IRQ5. DIAGNOSE /S is meant configure pre-PnP soundblasters, and it uses the BLASTER variable. So if BLASTER says I7, DIAGNOSE should configure pre-PnP-cards to IRQ7, not IRQ5.

HMM I don't know why diagnose is in the startup, the software installed it.

It's a CT2970

Thanks for your help so far!

Reply 6 of 6, by dr_st

Posted on 2021-09-24, 18:32

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kikendo wrote on 2021-09-05, 16:53:

I noticed a lot of games want the card to be in IRQ7 instead of 5 (like Martian Memorandum)

Not a lot - a handful (compared to the total number of games), and Martian Memorandum isn't even one of them - delete MM.CFG and the next time you run the game, you can configure settings, IRQ included.

But yeah, your configuration should work on IRQ7. If it's indeed a CT2970, it is PnP, and you should not need DIAGNOSE.

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