Hirsch wrote on 2022-02-23, 23:00:

I successfully tested the three files quoted with a Lin-Lin + Tualatin Celeron 1400 on CUBX and CUBX-L and with a Pentium II 450 on the P3B-F. (Something seems to be wrong with my Upgradeware SLOT-T + Tualatin Celeron 1400 on it. I'll check this later.) . The speed of a Noctua NF-8A slowed down to 1300 RPM is displayed correctly and no hardware error is reported during POST.

Excellent, thank you for the confirmations!

This is excellent work. Plan on putting it on my P3B-F when I get it up and running again, hopefully with a Celeron 1400.

I can also confirm that VIA C3 1.2A runs on CUBX-E with the latest 1008cul004_20220218 without serious problems. As mentioned, temperature reading is wrong, but this is not an issue for me.
Thanks for the mod, this will make a very interesting retro machine.

Any chance on such a bios for the Asus CUVX-M?

Will flash your BIOS very soon!

Thanks for all the continued endorsements and confirmations; they're much appreciated. 😀

Socket3 wrote on 2022-06-05, 14:53:

Any chance on such a bios for the Asus CUVX-M?

Hmm ... might be possible. From a quick glance, the BIOS builds seem similar. I don't own a CUV4X-M, though. Do you have the equipment to test the mod safely?

DenizOezmen wrote on 2022-06-05, 19:39:

Thanks for all the continued endorsements and confirmations; they're much appreciated. 😀

Socket3 wrote on 2022-06-05, 14:53:

Any chance on such a bios for the Asus CUVX-M?

Hmm ... might be possible. From a quick glance, the BIOS builds seem similar. I don't own a CUV4X-M, though. Do you have the equipment to test the mod safely?

Yes, I have an EEPROM reader and some spare EEPROMs. I can flash the new BIOS to another chip

Hi everybody!

This may be my last hope... I did rebuild my system from 21 years ago. The board is a CUV4X-CME running with a pinmodded SL6BY Tualatin. Everything went fine so far. One of the last things i wanted to do was unlocking some functions in the BIOS (FSB is grayed out, VCore not even present). My conclusion after trying it for days with every tool available and after reading a lot about BIOS modding: Reverse engineering by finding the correct hex values..
Deniz, could you help me out on this? (Unlocking the SET FSB alone would help me a lot.)

Can`t wait for ANY opinion!

Thanks

(BIOS attached)

Socket3 wrote on 2022-06-06, 08:14:

Yes, I have an EEPROM reader and some spare EEPROMs. I can flash the new BIOS to another chip

Great. Here's a first test. Let's see what is broken ...

[Edit 2023-08-03: Moved download off-site. See first post.]

VintageComputers wrote on 2022-06-06, 10:01:

Hi everybody!

This may be my last hope... I did rebuild my system from 21 years ago. The board is a CUV4X-CME running with a pinmodded SL6BY Tualatin. Everything went fine so far. One of the last things i wanted to do was unlocking some functions in the BIOS (FSB is grayed out, VCore not even present). My conclusion after trying it for days with every tool available and after reading a lot about BIOS modding: Reverse engineering by finding the correct hex values..
Deniz, could you help me out on this? (Unlocking the SET FSB alone would help me a lot.)

Hi,

it seems like this BIOS has been severely limited compared to its siblings. Is the board some kind of customized OEM model?

For example, it does not even have a VCore menu item, so there's nothing to enable or unhide.

Currently, my best guess would be that the BIOS might be stuck in a perpetual "non-jumperfree" mode. I have tried patching out the checks that could be found, but I'm not sure if this actually *does* anything, even if additional menu items should become available.

[Edit: Removed obsolete attachment.]

Thank you!

Gonna test it right away. Wish me luck.

The board - or at least similar layout - was released as the infamous OEM "MEDION 2001" around 2000. It is known as the CUV4X-CM because the very first BIOS had this written in the id string.

The CUV4X-CME from ASUS was released a little later. The only difference that i know is the southbridge, VT82C686A on the MEDION 2001 / VT82C686B on the CUV4X-CME.

UPDATE:

Just flashed it and system did post. Entering BIOS and i couldn`t believe my eyes! FSB is unlocked.

But, you probably guessed it already: Changes have no effect. So close after so many years, very annoying.

Thank you for trying to make it possible!

VintageComputers wrote on 2022-06-06, 15:16:

But, you probably guessed it already: Changes have no effect. So close after so many years, very annoying.

Thanks for testing! Yes, unfortunately, that was kind of expected. Should you happen to find something like unpopulated solder pads labeled "JEN" (or similar) on the board, chances might be better ...

DenizOezmen wrote on 2022-06-06, 10:43:

Socket3 wrote on 2022-06-06, 08:14:

Yes, I have an EEPROM reader and some spare EEPROMs. I can flash the new BIOS to another chip

Great. Here's a first test. Let's see what is broken ...

Sweet. I'll have a go at it tomorrow. Thanks

Hi!

I need a info are there tools/methods to customize ASUS P3B-F BIOS with custom "OEM" logo or picture?

Sorry, I am a noob in BIOS customization 😀

Babasha wrote on 2022-09-13, 08:17:

I need a info are there tools/methods to customize ASUS P3B-F BIOS with custom "OEM" logo or picture?

You can do two kinds of logo-related changes to the P3B-F BIOS: One possibility is to change the EPA logo in the upper right corner. The image format is severely restricted in terms of color choices, though. You can find a short tutorial e.g. here. There are several programs that can create the necessary EPA files, but not all of them produce compatible results. I verified that the EPACoder tool mentioned in that article works for the P3B-F. (Note: You will need to create a "Version 1" EPA file, contrary to what the article implies.) An example result can be seen in the first attachment.

The second possibility is adding a full-screen picture that replaces the POST screen. I wasn't aware of that until now (because it's not really documented), but the P3B-F also seems to support this feature. ASUS probably reserved it for certain mainboards, seeing that they only released their Logo tool for a few boards, but at least it worked on the P3B-F for one of the example images in the archive (see second attachment).

Hi DenizOezmen,

Thank you for your great work and the great BIOS for the ASUS P3B-F! I am using it and have no issues.
I recently made a video (Undervolted Pentium II) undervolting a Pentium II 400. The minimum voltage I can select is 1.55V - and the CPU is still stable.

I understand that there are voltage tables based on this post from you:

DenizOezmen wrote on 2021-09-12, 18:29:

Hmm, yes. I rebalanced the voltage tables a bit to enable the full undervolting range for cD0 Coppermine-T cores. The upper limit for 1.5V nominal voltage got lost in the process. I'll fix this.

Is there only a limited number of voltages that can be shown per CPU?
I was just wondering if it is possible to unlock more lower voltages or if there is a physical limit.

Thank you!

Hi!

BitsUndBolts wrote on 2022-11-21, 11:13:

Thank you for your great work and the great BIOS for the ASUS P3B-F! I am using it and have no issues.
I recently made a video (Undervolted Pentium II) undervolting a Pentium II 400. The minimum voltage I can select is 1.55V - and the CPU is still stable.

Thanks for the feedback!
Pretty cool video -- I wouldn't have expected such a low VCore to be usable. Also, it's interesting to see the exact point where the board applies the VCore setting.

BitsUndBolts wrote on 2022-11-21, 11:13:

I understand that there are voltage tables based on this post from you:

Yes. The board supports all required as well as optional voltages of Intel's VRM 8.1 through 8.4 specifications, and the BIOS has one table containing all 31 of them:

13.50V, 3.40V, 3.30V, 3.20V, 3.10V, 3.00V, 2.90V, 2.80V
22.70V, 2.60V, 2.50V, 2.40V, 2.30V, 2.20V, 2.10V, 2.05V
32.00V, 1.95V, 1.90V, 1.85V, 1.80V, 1.75V, 1.70V, 1.65V
41.60V, 1.55V, 1.50V, 1.45V, 1.40V, 1.35V, 1.30V

BitsUndBolts wrote on 2022-11-21, 11:13:

Is there only a limited number of voltages that can be shown per CPU?
I was just wondering if it is possible to unlock more lower voltages or if there is a physical limit.

There's no physical limit that I am aware of. The only limitation is GUI space. I'm not sure whether the dropdown menus support scroll bars, so I chose to go with the maximum number of lines I found evidence for, which is 16. (Sometimes only 15 are displayed, because there's a hidden invalid setting between 2.05 V and 2.10 V.)

So the BIOS basically chooses a maximum allowed (over)voltage setting depending on the processor VID and then fills up the rest of the list with as many entries as supported by the GUI.

I might try and see what happens when the 16 line limitation is removed.

By the way, you can alter and build the modified BIOS by yourself, if you like. You only need to download a copy of NASM, everything else is included in the archive. (Even if the GUI limit stands, lower voltages could still be unlocked by sacrificing a few overvoltage settings and simply shifting the voltage window downwards.)

Thanks for you answer!

I may give modifying the BIOS myself a shot in the future. I have a few replacement BIOS chips on the way - will be doing some experiments with hot swaps, boot blocks, and replace this EPA Energy Star logo...
I'll definitely bookmark this thread for its useful information!

BitsUndBolts wrote on 2022-11-22, 16:39:

I may give modifying the BIOS myself a shot in the future. I have a few replacement BIOS chips on the way - will be doing some experiments with hot swaps, boot blocks, and replace this EPA Energy Star logo...
I'll definitely bookmark this thread for its useful information!

Have fun!

In the meantime, I was curious and tried a build without the 16 line limit. Lo and behold - it scrolls! 😉

I haven't actually tried the "new" settings, but don't currently see a reason why they would not work. You can give it a shot if you like:

[Edit: removed obsolete attachment]