AMI BIOS M726MRT won't release VGA IRQ

[oalexandre]

I've got a PCChips M726MRT mainboard (ALi M1621/M1533 chipset and sound chip CMI 8738) with an 128K AMIBIOS. It has 3 PCI slots, so PCI IRQ routing table has 4 entries plus one hardwired to USB controller's IRQ. The problem is that, although BIOS Setup allows you to disable IRQ assignation for VGA (AGP bus), it gets always an IRQ, occupying the first entry in the table, and the result is that onboard sound chip's IRQ always clashes with PCI Slot 3 device.

[ajzchips]

Depending on how old your M726mrt BIOS is, it may have a problem that's similar to what the M726 experienced (same chipset), and a BIOS release solved the following problem (for the M726):

NEW RELEASE *
FILE NAME : 990722S.ROM
CHECKSUM : 7A7B H
FIX BUG : Support Windows 98 SE alway Assign IRQ For VGA.

This of course doesn't mean that the BIOS didn't display "N/A" for VGA IRQ; it most probably did, but perhaps disabled the IRQ incorrectly, so Win98SE somehow managed to reactivate it.

Perhaps a newer BIOS release will release the IRQ correctly, so give it a go.

If you can, try getting a 2Mbit BIOS chip, because the latest (2000 & 2001) releases are 256KB in size. The latest 128KB BIOS is of late 1999.

[oalexandre]

Apparently, the BIOS you've just mentioned is for the M726 mobo, NOT M726MRT

I've already flashed M726MRT 128K last version (991204S), without any change. It's not a Win98(SE) problem, it's a big BIOS bug.

[NickS]

Apparently, the BIOS you've just mentioned is for the M726 mobo, NOT M726MRT

I can tell you did not read AJZchips's post properly.