Re: My youtube channel: Necroware
Posted on 2022-02-01, 16:53
Okay, I will start working on it. When tested, I will also put the patched BIOS on my Unoffical K6-2+ / K6-III+ page. Jan
Re: My youtube channel: Necroware
Posted on 2022-02-01, 16:43
I think many of you guys already have seen my last two videos about one of the projects I've been working on recently. But just in case someone missed it and is curious here is the link: Part 1: https://youtu.be/CMiGVQbMC5U Part 2: https://youtu.be/J0NLGfocviU Hi scorp, Thanks for your great 2 …
Re: PC Chips M912 BIOS update for Am5x86 and Cyrix 5x86
Posted on 2022-02-01, 11:28
Would it be possible to do the same with the AMI Bioses, the original 12/01/1995 and the weird 12/02/1995X which no1 knows where it came from? Hi Am386DX-40, Alas, I have little experience with the AMI BIOS. I did a few AMI socket 7 BIOS patches for K6plus support and once I disassembled an 011094 …
Re: Diy modding support for k6+And 120gb hard drives into bios roms
Posted on 2022-01-31, 11:21
Hi 386SX, I've checked this PCPartner MB520NH, VXB810DS, VXB820DS, VXB830DS 08/14/97 BIOS and yes, I can patch it for: - K6-2/ K6-III/K6-2+/K6-III+ support - Write-Allocation support for K6-2CXT/-III/-2+/-III+ - CPU speed support above 333MHz up to 450MHz - 32GB and 64GB bugfixes for 128GiB HDD …
Re: The coolest socket 7 motherboard that you’ve never heard of
Posted on 2022-01-30, 15:42
Hi Sphere478, you requested my take on the 5VGF+/Ultra board and BIOS, so here is my 2 cents. ;) I see that they upgrade the VIA south-bridge from 586B to 686A. The 586B limited you to UDMA33, but with the VT82C686A you get UDMA66 support on the IDE channels, 2 more USB ports, and Audio. Although …
Re: AMD 5x86 P75 on Chaintech 4SPI
Posted on 2022-01-28, 19:16
Yes, the Am5x86-P75 supports both the Write-Through and Write-Back mode for its L1 cache. But often the Write-Back mode gives boot problems when the BIOS doesn’t know the Am5x86. That’s why I recommended to set the jumpers to DX4, so the Am5x86 runs in x3 and WT mode. This should always work if the …
Re: AMD 5x86 P75 on Chaintech 4SPI
Posted on 2022-01-28, 15:12
Hi kolmio, Well, an Am5x86-P75 should work on the Chaintech 4SPI board. To test if the Am5x86 CPU is OK, be sure to check if there are no jumpers on JP24. This will put the Am5x86 in x3 mode and it should run at 100MHz on the 33MHz bus. If you had an Intel DX4 or Enhanced Am486DX4 on this board …
Re: Early P5 + P54C (Socket 4 + Socket 5) mainboard
Posted on 2022-01-28, 12:55
@LocalBus, If you have an (E)EPROM programmer, can you make a BIOS copy from the EPROM chip? I would love to poke around in the Award BIOS from this unique board, and I should be able to tell you exactly what the BIOS is doing in POST 0A. 😉 Jan
Re: Need Bios Help with Jetway / J-Mark J446B mainboard
Posted on 2022-01-27, 21:23
Okay! 😀 Glad I could help. Jan
Re: Diy modding support for k6+And 120gb hard drives into bios roms
Posted on 2022-01-27, 10:25
Okay, that MB-1433UHT-A is a nice board with indeed both VLB and PCI slots. :) Thanks for the "take2" BIOS dump, looks perfect! It’s an interesting BIOS for my Am5x86 patch story as well. When I look at the Reset_ID table I see that the sequence of the items is different from my previous example. It …
Re: Diy modding support for k6+And 120gb hard drives into bios roms
Posted on 2022-01-26, 16:48
Biostar MB-8433UHT-A? Typo perhaps? Would that be an MB-1433UHT-A board, like on https://www.ultimateretro.net/en/motherboards/1090 If so, is it the 12/21/94-UMC-881/886-2A4X5B01-00 BIOS you are going to patch? Unfortunately, the copy of this BIOS on Ultimate Retro is corrupt. Its missing the first …
Re: Diy modding support for k6+And 120gb hard drives into bios roms
Posted on 2022-01-25, 11:42
Hi turbooo, Welcome to the league of BIOS patchers! ;) This December 1994 Award BIOS probably has the Year 2094 and 2GB HDD display limit bugs as well, so you may also want to patch these while you’re at it. For which board are you patching this BIOS? Just curious… As you probably know, the Cyrix …
Re: Diy modding support for k6+And 120gb hard drives into bios roms
Posted on 2022-01-24, 21:44
The x4 multiplier During POST, just after the BIOS has measured the CPU speed, there is a routine that determines the bus_speed (FSB). This bus_speed value is then used to program the chipset’s DRAM and L2 cache timing registers for optimum performance and stability. The BIOS calcutates the bus_ …
Re: Diy modding support for k6+And 120gb hard drives into bios roms
Posted on 2022-01-24, 21:33
Patching for new CPU models Okay, now we need to decide what needs to be changed to support the Am5x86 CPU. Because the BIOS_uP_ID is used in multiple places during POST to make decisions depending on the CPU model, the most effective way to add Am5x86 support to a 1994 BIOS is to let the BIOS …
Re: Diy modding support for k6+And 120gb hard drives into bios roms
Posted on 2022-01-24, 21:22
#Part 4 – What to patch in an uncompressed Award BIOS – cont’d In this episode, I will talk about what you can do to get better Am5x86-133 support in your 486 Award BIOS. However, this will be a rather complex story, because Award Software made a lot of changes to its 486 BIOS during the 1994-1995 …
Re: Modded BIOS K6-2+ question.
Posted on 2022-01-22, 12:29
@TrashPanda, thanks for supporting my website. :) You are correct, most BIOSes I’ve patched for K6-2+/-III+ already have support for the original K6-2/K6-III CPUs. But if they don’t, I have added K6-2/K6-III support as well so all BIOSes on my k6plus page support the K6-2/K6-III/K6-2+/K6-III+ models …
Re: Winchip C6 C6-PSME200GA, multipler adjustable?
Posted on 2022-01-19, 18:17
Yes, the IDT Winchip C6 multipliers are unlocked. But this CPU supports only whole multipliers of x2, x3, x4, and x5. In the attachment you'll see what IDT wrote in the C6 databook. The Winchip 2 has the same multipliers specification, but the Winchip 2A can do fractional multipliers and some …
Re: PC Chips M912 BIOS update for Am5x86 and Cyrix 5x86
Posted on 2022-01-18, 15:09
Can we ask for other modifications? Like HD size? Hi Nexxen, You can always ask but no, I never modified a BIOS to break the 8GB HDD barrier. As you probably know, such a mod would involve adding the IBM/Microsoft Int 13h extensions to the Int 13h interface. As the BIOS Interrupt 13h handler is …
Re: PC Chips M912 BIOS update for Am5x86 and Cyrix 5x86
Posted on 2022-01-17, 20:35
As this was the first time I did a patch to correct a fake cache BIOS, I requested one member to test it, before making this patched M912 BIOS public. @weedeewee, thanks for this first test! I’m glad that the different cache sizes are now indicated correctly. :) Here is the DX-6900/M912 VER 2.21r …
Re: PC Chips M912 BIOS update for Am5x86 and Cyrix 5x86
Posted on 2022-01-15, 21:03
weedeewee, Oh my, your L2 cache troubles revealed the DX-6900/M912 VER 2.21r BIOS to be a “fixed” BIOS for fake cache boards!! I’ve been looking into the BIOS code for the past hour, comparing it with known good UMC498 BIOSes, and I believe I found the sneaky always 256KB Cache Memory patch! :) It …
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