IRQ9 cascades to IRQ2, so they are essentially the same. Using IRQ9 and IRQ2 for different (ISA) devices will result in a resource conflict. That's why IRQ2 doesn't turn up in the PnP settings in the BIOS setup. On some mainboards the ACPI controller is hardwired to IRQ9.
It is generally a good idea to leave IRQ2 untouched and only use IRQ9.

Thank you for helping out!

I will jumper the MPU401AT to IRQ5, a setting I know that works. The Sound Blaster Pro 2 is on IRQ7. I tried my usual Roland games, Wing Commander, Space Quest 3, Heart of China and Monkey Island 2 and they all work fine.

It seems that only Legend is actually using (checking) the IRQ of the MIDI interface. I will keep an eye on it and hopefully all works well 😀

pyrogx wrote:

IRQ9 cascades to IRQ2, so they are essentially the same. Using IRQ9 and IRQ2 for different (ISA) devices will result in a resource conflict. That's why IRQ2 doesn't turn up in the PnP settings in the BIOS setup. On some mainboards the ACPI controller is hardwired to IRQ9.
It is generally a good idea to leave IRQ2 untouched and only use IRQ9.

To further add to that, ACPI is hardwired to use IRQ9. If your motherboard has an option to switch to APM mode, use it as it will free up IRQ9 for other uses. ACPI is more trouble than its worth on desktop machines, particularly early implementations (circa 1998-2000 motherboards).

Wasn't this cascading IRQ issue when ISA bus cards went from 8-bit to 16-bit and they needed IRQ's 0 ~ 15 ?

I think the design was such they had to cascade one of the 8-bit IRQ's to pass along for proper 16-bit support.

No, it was implemented just because there were more and more types of devices and more and more people wanted to have all the multimedia stuff in their PCs and the 0-7 IRQs with integrated devices in it was just not enough.

But your theory is interesting, if you could please elaborate, never heard of this alternate purpose.

As for the issue, I think the game is pretty much demanding the proper old environment it just simply refuses to work. It's in the code, but whyyyyyyy ???? Who benefits from such obstacles...

NJRoadfan wrote:

To further add to that, ACPI is hardwired to use IRQ9. If your motherboard has an option to switch to APM mode, use it as it will free up IRQ9 for other uses. ACPI is more trouble than its worth on desktop machines, particularly early implementations (circa 1998-2000 motherboards).

I will check the BIOS when I get back home. In the meantime using IRQ5 for the MPU401 has been working with all the games I tried.

I'm glad you could solve your problem.

Today I dug up an old controller from Adaptec, an ASH-1205SA PCI with a SiI 3112A chip and 2 SATA ports. I've been trying to use those horrible 2-ways IDE-SATA converters, with all kinds of weird and frustrating issues.

It runs pretty decently, I managed to update the firmware to the latest version available, but I was disappointed when I found out there is no way to boot from a CD/DVD, and no way to use a CD/DVD plugged into that card in DOS.

So I'm wondering, does anybody know about a PCI controller supporting 2 SATA ports, that can boot from a SATA DVD-ROM?

All help is greatly appreciated. I'm running out of ATA drives/DVDs, and prices for new ones are ridiculous (55 Euros for an ATA DVD).

I use and recommend IDE optical drives because of the need for analogue audio out. I haven't see a SATA drive with analogue audio outputs at the back...

Mau1wurf1977 wrote:

I haven't see a SATA drive with analogue audio outputs at the back...

I was just looking for one, too, and I'm pretty sure that they don't exist.

Good thing is there are a TON of drives available and I don't see them becoming rare any time soon.

Well I haven't been able to resolve this issue.

Decided to go back go using CF cards on the mainboard's IDE controller. Now there is no IRQ conflict with the MPU401AT when playing Gateway.

Funny how one game not working can bug you to the point of changing your system again 😀

Got a 32GB CF card coming from eBay. Hopefully it works well and I have no dramas.

Mau1wurf1977 wrote:

Well I haven't been able to resolve this issue.

Decided to go back go using CF cards on the mainboard's IDE controller. Now there is no IRQ conflict with the MPU401AT when playing Gateway.

Got a 32GB CF card coming from eBay. Hopefully it works well and I have no dramas.

Have you tried with SoftMPU?

In my system i have disabled the secondary IDE channel. So my display is on IRQ 15 and PCI SATA controller is on IRQ 11. ACPI is disabled.

I would test the same configuration on my system but i don't have a Roland MPU-401AT.

Funny how one game not working can bug you to the point of changing your system again 😀

I hardly remember how many times i changed stuff around because of this...

On the Ggiabyte and Iwill boards, ACPI is hardwired to IRQ2/9. For some reason, if I use the PCI SATA controller card, Gateway will lock up with the MPU401AT unless I configure it at a different IRQ.

I have an Aopen board which allows disabling ACPI. This is the AX59Pro and the only board I have that works with the MPU401AT and SATA controller.

But I rather not change the board, so I'm going back to CF cards.

Mau1wurf1977 wrote:

On the Ggiabyte and Iwill boards, ACPI is hardwired to IRQ2/9. For some reason, if I use the PCI SATA controller card, Gateway will lock up with the MPU401AT unless I configure it at a different IRQ.

I have an Aopen board which allows disabling ACPI. This is the AX59Pro and the only board I have that works with the MPU401AT and SATA controller.

But I rather not change the board, so I'm going back to CF cards.

I see you love that Gigabyte. I'm using this one:

Awesome DFI board with 3 ISA slots. And you can disable ACPI.

Very nice!

I must say I haven't found affordable SS7 boards lately. I guess me promoting them didn't help either 😀

thanks to this thread and Mau1wurf1977's discovery I turned completelly OFF acpi on my p200mmx build and some mpu troubles went away (no ide/sata controller installed at all)

Mau1wurf1977, i guess this is what you need:

I've just modded the latest version available of the Gigabyte GA-5AX BIOS, to include ACPI option to enable/disable:

ATTENTION:

USE THIS BIOS FILE AT YOUR OWN RISK!!!!

I did not alter any BIOS code, i just made ACPI active on the screen to allow enable/disable option!! It should work fine, but flashing is always a risk!

EDIT: Removed file as it is now obsolete.

Oh dear.

Just tried it and it bricked the board 😢

It does a few PC speaker beeps and then hangs. Floppy LED is lit.

Will have to do a BIOS hotflash on another board I guess.

What could have gone wrong?

I see you use a BIOS editor. Might have a play with this myself...

Mau1wurf1977 wrote:

Oh dear. […]
Show full quote

Oh dear.

Just tried it and it bricked the board 😢

It does a few PC speaker beeps and then hangs. Floppy LED is lit.

Will have to do a BIOS hotflash on another board I guess.

What could have gone wrong?

I see you use a BIOS editor. Might have a play with this myself...

😠
How many beeps?

I was pretty sure it was gonna work... Anyway, we can get your board easily back online. I have an EEPROM burner.

Did you use AWDFlash? Maybe something went wrong in the flashing process. I will have a Gigabyte GA-5AX in the future so i'll be able to test as well.

EDIT: I just used that editor to confirm everything was good.

I used AWDhack with MODBIN to actually make the ACPI visible.