The corner of my brain with the weak read heads and bad sectors wants to tell me I might have seent it on a SiS635 P4 board, but not very certain of it.

BitWrangler wrote on 2021-09-24, 18:06:

The corner of my brain with the weak read heads and bad sectors wants to tell me I might have seent it on a SiS635 P4 board, but not very certain of it.

Good idea doubting, as i couldn't find anything for a SiS 635 4.51PG anywhere online. Maybe it's a variation but i doubt it. The latest SiS i found that runs 4.51PG is SiS 620, but there is a chance 621 may run it too.

On another note, there was a manual for an IEI "Rocky" SBC that ran AMIBIOS 6 and used SiS 651, so i wouldn't say it's necessarily impossible. (maybe iei made a 4.51pg pentium 4 too, who knows)

IIRC, EPoX also used 4.51 on the EP-3VCM I have, though newer subsequent releases run 6.00PG I think.

As for AMIBIOS 6, I have a strong feeling ASRock used it up until they implemented i848P/865P/PE/GV Pentium 4 solutions. IIRC all their Socket A mobos use AMIBIOS 6 I think (or a close variation with a interface similar to ASUS' Medallion/WorkstationBIOS 6.00PG, present on CUSL2/TUSL2 series up to any AM2/775 mobo that used AwardBIOS exclusively, i.e M2A-VM, M2N-SLI, M2N-E as well as P5N-MX, P5N-E SLi)

Intel chipset wise - 440BX is the last to run 4.51 AFAIK, with ABIT and ASUS adopting 6.00PG late in its life.
AMD - I think it might be Super Socket 7 only, as I think that starting with Slot A, all chipsets use 6.00PG.

PcBytes wrote on 2021-09-24, 19:22:

IIRC, EPoX also used 4.51 on the EP-3VCM I have, though newer subsequent releases run 6.00PG I think. […]
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IIRC, EPoX also used 4.51 on the EP-3VCM I have, though newer subsequent releases run 6.00PG I think.

As for AMIBIOS 6, I have a strong feeling ASRock used it up until they implemented i848P/865P/PE/GV Pentium 4 solutions. IIRC all their Socket A mobos use AMIBIOS 6 I think (or a close variation with a interface similar to ASUS' Medallion/WorkstationBIOS 6.00PG, present on CUSL2/TUSL2 series up to any AM2/775 mobo that used AwardBIOS exclusively, i.e M2A-VM, M2N-SLI, M2N-E as well as P5N-MX, P5N-E SLi)

Intel chipset wise - 440BX is the last to run 4.51 AFAIK, with ABIT and ASUS adopting 6.00PG late in its life.
AMD - I think it might be Super Socket 7 only, as I think that starting with Slot A, all chipsets use 6.00PG.

About AMIBIOS 6, we know it's been used on i850 boards from both MSI and Gigabyte, both running either Socket 423 or 478 configurations (the socket 478 ones being harder to find), and the Rocky SBC that runs SiS 651.
For Intel, i know 440ZX also recieved 4.51PG, which itself released later than 440BX so i'd say Intel chipsets stopped running it at 440ZX. I haven't seen an AMD 4.51PG, but i also haven't looked much into them. ASRock is a good guess, considering their long adoption of AMIBIOS 7, but i haven't checked. I've also never heard of the EPoX described above, but looking online it seems to be another Apollo Pro 133A, although it's possible that it's chipset + southbridge combination is different.

explorerdotexe wrote on 2021-09-24, 20:25:

PcBytes wrote on 2021-09-24, 19:22:

IIRC, EPoX also used 4.51 on the EP-3VCM I have, though newer subsequent releases run 6.00PG I think. […]
Show full quote

IIRC, EPoX also used 4.51 on the EP-3VCM I have, though newer subsequent releases run 6.00PG I think.

As for AMIBIOS 6, I have a strong feeling ASRock used it up until they implemented i848P/865P/PE/GV Pentium 4 solutions. IIRC all their Socket A mobos use AMIBIOS 6 I think (or a close variation with a interface similar to ASUS' Medallion/WorkstationBIOS 6.00PG, present on CUSL2/TUSL2 series up to any AM2/775 mobo that used AwardBIOS exclusively, i.e M2A-VM, M2N-SLI, M2N-E as well as P5N-MX, P5N-E SLi)

Intel chipset wise - 440BX is the last to run 4.51 AFAIK, with ABIT and ASUS adopting 6.00PG late in its life.
AMD - I think it might be Super Socket 7 only, as I think that starting with Slot A, all chipsets use 6.00PG.

About AMIBIOS 6, we know it's been used on i850 boards from both MSI and Gigabyte, both running either Socket 423 or 478 configurations (the socket 478 ones being harder to find), and the Rocky SBC that runs SiS 651.
For Intel, i know 440ZX also recieved 4.51PG, which itself released later than 440BX so i'd say Intel chipsets stopped running it at 440ZX. I haven't seen an AMD 4.51PG, but i also haven't looked much into them. ASRock is a good guess, considering their long adoption of AMIBIOS 7, but i haven't checked. I've also never heard of the EPoX described above, but looking online it seems to be another Apollo Pro 133A, although it's possible that it's chipset + southbridge combination is different.

UPDATE: A Slot A 4.51PG has been found! And it uses an AMD chipset. (AMD 750 Irongate) http://www.win3x.org/uh19/motherboards/7905

Turns out, it's more than one. Here's the ASUS K7V, which uses their 4.51PG fork also for Slot A. (VIA VT8371) http://www.win3x.org/uh19/motherboards/8494

Well, color me surprised. I legit never expected that ASUS and MSI had 4.51 on their AMD751 iterations, and thought that MSI used the usual 6.00PG and ASUS used Medallion (similar to their CUSL2 and TUSL2 boards.)

As for the EPoX I listed: 694X + 686A. Basically a mATX 694X mobo, and it's fast and stable at that. Just as long as it's recapped, as usual.

PcBytes wrote on 2021-09-25, 05:49:

Well, color me surprised. I legit never expected that ASUS and MSI had 4.51 on their AMD751 iterations, and thought that MSI used the usual 6.00PG and ASUS used Medallion (similar to their CUSL2 and TUSL2 boards.)

As for the EPoX I listed: 694X + 686A. Basically a mATX 694X mobo, and it's fast and stable at that. Just as long as it's recapped, as usual.

Well, i looked into the BIOSes and unfortunately they seem to be mislabels. The ASUS is 6.0 Medallion and the MSI is 6.00PG. So the search continues.