just a small followup, so apparently I only have 1mbit eeprom and the one they used is an ATMEL AT29C010A 12PC 9820. I guess I will have to try to find some 2mbit compatible eeprom to pursue that project. The v1.3 bios see some of my 32gb CF cards as 8gb and some as 32gb so maybe it will help in that regard. I'll try to report on that when I eventually get some 2mbit eeprom ...

another update, I found an M29F002NT from ST but the bios booted with the strangest beep code : it was one long high pitch beep followed by two short high pitch beep then a rather long pause (like maybe 1 sec) then a medium pitched beep followed by a low beep, and then no post. I guess that either mean that board need an ATMEL 2mbit eeprom or that board revision cannot read 2mbit chip. Now I'm less certain buying some chip is a good idea.

Hi ElBrunzy,

Although I’m unfamiliar with this 6IBA board, I do know a lot about the Award v4.51PG BIOS it uses.

I have been looking into the v1.3 and v1.4 BIOSes to see what is changed.
The 128KB v1.3 BIOS has only 1.87KB of code space left, so no wonder they went for a 256KB BIOS with v1.4, to make room for the update.

A few BIOS SETUP options are updated, but nothing major.

The CPU support of both v1.3 and v1.4 is the same, however v1.4 has updated microcodes for several Pentium II models. These microcode updates come from Intel and fix known CPU errata.
Which CPU are you using and what is its CPUID?

An important limitation in both v1.3 and v1.4 is the infamous Award 32GB IDE HDD limit bug. I can fix this bug in either BIOS version if you need full 128GiB/137GB support.

Then there is the UDMA mode bug. This bug causes Win98(SE) to revert to PIO mode 4 when an UDMA66 or faster drive is used.
BIOS v1.3 has this bug, but it is fixed in BIOS v1.4. In my view, this bugfix alone warrants an update to v1.4!

I have no information about an incapability of the M29F002NT with this board, but I believe 2Mbit EEPROMs like AT29C020, or W29C020 should work.

Cheers, Jan

Thanks for you reply Chkcpu ! I highly appreciate the information you provide as it is exactly what I was looking for. I agree with you the PIO mode 4 bug alone deserve that upgrade and it bolster my effort at doing it (as those CF are udma5), this bug always puzzled me and now I can understand the situation. I have found >32gb patch but only for the 1mbit bios so I think it would be a nice value if you do it for the 1.4 and post it here.

I have found two 2mbit eeprom yesterday and I am wishing to try them today. They are from working board so it would only be for a test. I'm still searching why the board did not accepted that 2mbit ST eeprom, my only guess now is that there is some communication difference between the ST and ATMEL eeprom.

Considering all the effort I'm deploying to upgrade that board now I would be glad to introduce the 128/137gb support fix, while I only use a 32gb CF card that would shield it for the future. I'm also ready to bet that there is more chance some rogue 32gb CF card appearing as 8gb drive on the bios would be fixed by the patch you mention rather than the 1.4 upgrade now.

I did try 2 more 2mbit chip (AE29F2008 and SST39SF020) and this board still dont post. I have now the conviction that buying ATMEL 2mbit chip wont help this board as this revision 1.1 probably simply do not accept 2mbit eeprom, maybe it's missing a trace or some such... oh well, just too bad. Maybe there is another way to fix that UDMA bug in win98se.

ElBrunzy wrote on 2025-12-13, 21:10:

I did try 2 more 2mbit chip (AE29F2008 and SST39SF020) and this board still dont post. I have now the conviction that buying ATMEL 2mbit chip wont help this board as this revision 1.1 probably simply do not accept 2mbit eeprom, maybe it's missing a trace or some such... oh well, just too bad. Maybe there is another way to fix that UDMA bug in win98se.

Hi ElBrunzy,

Now that your 6IBA board revision appears not to support 2Mbit EEPROMs, I went ahead and patched the 128KB V1.3 BIOS.
I was able to fit both the 32GB HDD limit and UDMA mode bug fixes into this 128KB BIOS, so this patched BIOS now supports IDE drives up to 128GiB/137GB and UDMA mode 2 on UDMA 4/5/6 drives under Win98(SE).

Here is this V1.3 patch J.1 BIOS and in the zip I’ve included a PATCH.TXT file that lists the changes I’ve made. Please let me know how this BIOS works.

Cheers, Jan

that's ... I ... wow ! I'm speechless, that's such an unexpected good news, I do not know what to say but it's only because I'm so happy. So, thank you !

I read that you could set the bios in PIO4 mode and it would let windows use DMA correctly so I wanted to try that, even if it had worked, I'm not sure of the impact in msdos and nt2k as this computer multi-boot. There is also the possibility to use an PCI2IDE cards but I prefer to reserve those for when a bios simply do not see the media correctly.

I will want to conduct some test to really appreciate the impact of that fix. I'll get back with the results as soon as possible.

ElBrunzy wrote on 2025-12-14, 22:45:

Thank you !

You’re welcome. Yeah, the past 25 years, this BIOS patching became quite the hobby. 😉
On my “The Unofficial K6-2+ / K6-III+ page” (link is in my signature below) you can read the story about the Award 32GB IDE HDD limit bug and its fixes. This applies to both Socket 7 and Slot 1 1998-1999 era Award v4.5x BIOSes.

The “new community fix” described on my page is the one I applied to your 6IBA v1.3 BIOS. This fix supports IDE drives up to 128GiB and allows drives up to 640GiB to be attached, although the BIOS will then only 'see' the first 128GiB due to the 28-bit LBA limitation.
When a larger than 128GiB drive is used, this fix is intelligent enough to limit the detected drive parameters to within the LBA28 limit automatically.

I read that you could set the bios in PIO4 mode and it would let windows use DMA correctly so I wanted to try that.

Actually, setting the BIOS to disable UDMA would have worked as a work-around to get and keep DMA selected in Win98 device manager. But this would get you Multi-Word DMA at best, less than half the speed of UDMA33 and only slightly faster than PIO4.

Happy testing, Jan

So today I did the benchmark with the standard v1.3 unpatched bios. I did screenshot but I think it will be simpler to just write down the summary here. What I can confirm is that in UDMA5, windows 98 would untick the DMA checkbox in the device properties. In PIO4 mode, the DMA checkbox would remain ticked. It seem clear that win2k is unaffected by that problem. DOS seem affected by the mitigation solution, making your patch even more pertinent and I wish to thank you again for that. Now that I have those numbers and the confirmation that the bug clearly affecting the system, I will install your patched bios later this week and report back with the analysis.

win2000 :
- Bios mode : DMA5 = 25mb/s
- Bios mode : PIO4 = 25mb/s

win98 :
- Bios mode : DMA5 = 8mb/s (DMA in device property is unchecked)
- Bios mode : PIO4 = 14mb/s (DMA in device property is checked)

dos :
- Bios mode : DMA5 = write 3mb/s, read 4mb/s, 8k 187IOPS, random 1162IOPS
- Bios mode : PIO4 = write 0.5mb/s, read 4mb/s, 8k 48IOPS, random 139IOPS

Tonight I could install the J1 patch and conduct the test. On the BIOS POST report you could see that it's set to UDMA2, with that and the text file you kindly wrote I understand better what you did, nevertheless I feel so lucky you took the time to repair that problem on my motherboard BIOS. Because, yes, the benchmark and behavior of win98se clearly show that the hardware is now utilized at their maximum by the operating system !

win2000 :
- Bios mode : DMA2 = 25mb/s

win98 :
- Bios mode : DMA2 = 24mb/s (DMA in device property is checked)

dos :
- Bios mode : DMA2 = write 3mb/s, read 4mb/s, 8k 145IOPS, random 1164IOPS

Thanks for reporting back with the patch J.1 BIOS benchmarks. A marked improvement indeed, and exactly right for Win98(SE) on this board! 😀

I will now send this BIOS to TheRetroWeb for the benefit of other 6IBA users.

Season greetings,
Jan