Which HOT-433 PCB revision is this BIOS for? Does it work well with Windows? How do you know this BIOS is for the HOT-433?

Hi!
Sorry for creating a new account, but it seems, I've forgotten my password 😒 But sending a new one says after clicking on the user: no such user..
To answer you question. I've hat a HOT-433 Rev 1.x to 3.x. Its not the smaller 4.0. Windows 95 was running fine, but it was just a test installation. I don't know, if its really for a HOT-433, but I got it sent if from a friend, which also owns a HOT-433 and he told me, this one would be for a HOT-433..

Can you test the PS/2 mouse feature on it? According to ModBin, this particular BIOS has PS/2 mouse option enabled by default in the BIOS.

I can try. But this will take a few days, as I don't have any PS/2 mice here and have to borrow it from a friend.
But. Isn't it so, that PS/2 works only, if there would be a second IC on this big empty socket?

omgwtfbbqlol2 wrote:

I can try. But this will take a few days, as I don't have any PS/2 mice here and have to borrow it from a friend.
But. Isn't it so, that PS/2 works only, if there would be a second IC on this big empty socket?

It may be that the keyboard and PS/2 controller chip is part of the UMC chipset. The MB-8433, for example, has no keyboard controller chip (the one that you speak of) on the PCB. The PS/2 header traces go to the UMC chipset. I think the HOT-433 v4 also has no keyboard controller chip.

Hi!
I've flashed this BIOS on mine HOT-433 😀
Its quite interessing. Its Version 4.51PG and dated from 2001.

Booting from CD-ROM is working. 1024K Cache ist detected.

Very nice is also:
Am5x86 ist correct detected.
There is no 8GB Limit. Bios is my 120GB correctly detecting!

But there a problem. I had to disable PS/2 with modbin, as after flashing, the keyboard connected over AT wasn't working. Like dead.
I don't have any PS/2-header, to test it. Maybe a PS/2-Keyboard? would work.

...

How do we know that this BIOS is really for the HOT-433 v1-3? I did not see anything in the readme refering to HOT-433. The 1024K may not be detected because you need to set your Alt Bit in TAG SRAM to 8+0 instead of 7+1.

Enabling PS/2 support in the BIOS with ModBin probably won't work on its own. I did some analysis on this a few months back. I'd need to dig through some e-mails to find out exactly what the problem was, but from memory, they did not connect the PS/2 data and clk pins to the proper locations on either the i8042 or the southbridge. I think they tried to gang up the data line for keyboard and PS/2 mouse ports, which will not work on either the i8042 or UM8886 southbridge. v4.0 of the HOT-433 changed their ps/2 pin locations, but they still did not get it right. Some simple PCB rewiring may be all that it takes.

I know on late 1995 and 1996 southbridge UM8886 chipsets, the mouse data goes to pin 199 and clock goes to pin 200. I am not sure if these early 1995 UMC southbridge chipsets had PS/2 support or not. Maybe they do? If they did, you'd need to wire the mouse data/clock to pins 199/200 and add PS/2 voltage and ground. I'd probably try this out with the old HOT-433 BIOS first using MODBIN. FYI, keyboard data/clock goes to UM8886 pins 56/57. I have noted this on the latest version of my Biostar MB8433-UUD manual, which can be found in the World's Fastest 486 link.

Unfortunately, I no longer have time to monkey around with hardware. Best of luck with this!

I don't know if its really for the HOT-433.
But in the 433WIE10-Bios, you can find the ID-String "2a4x5h21".
This one is also in this Bios here. At least I would asume so.

Am I correct, that I need a 10Pin Header for a PS/2-Braket?

ConiKost wrote:

I don't know if its really for the HOT-433. But in the 433WIE10-Bios, you can find the ID-String "2a4x5h21". This one is also in […]
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I don't know if its really for the HOT-433.
But in the 433WIE10-Bios, you can find the ID-String "2a4x5h21".
This one is also in this Bios here. At least I would asume so.

Am I correct, that I need a 10Pin Header for a PS/2-Braket?

No. You only need to solder in 4 pins for the header. But there is no point in this. If you want a working PS/2 port, you'll need to experiment with the options I noted in the previous post.

I have not seen a HOT-433 v1-3 without the actual PS/2 header soldered on. Maybe you have one of the later editions, whereby the manufactorer realised their PS/2 implementation did not work. What are your chipset datecodes?

Sorry, due my bad english, i haven't described it correctly.
My board has the 10-Pin header soldered on mainboard.

I meant the 10-Pin -> PS/2 Port Slot-"Adapter". Sorry 😒 I don't have one, but would need to play with it and you noted in your previous post.

This BIOS is working fine, but it seems its for rev. 1-3, FDD is not responding on v4 motherboard and with 433WIE10 too. PS/2 must be disabled with Modbin before flashing.

I made the mistake of flashing this BIOS to my board last night, without reading the entire thread. Sure enough, it boots up awesomely, but I can't do anything with it because the AT keyboard is dead. And no, using a PS/2 header doesn't magically make the keyboard work, since it's wired up incorrectly on the board. Luckily I was able to flash the chip back using a P5 board and some hot swap trickery.

BTW the BIOS appears to be from esupport.com. I had thought this site was mostly a scam, but apparently not.

Does this BIOS actually work when modifying it with Modbin? The poster above me seems to think so, but I'm hesitant to try flashing it again since it was such a pain to swap-flash.

I recommond getting an EEPROM writer board. Good for stress relief in future dealings.

Here is modified Award BIOS for HOT-433 from this thread with disabled PS/2, default EPA logo, modified BIOS message - "Shuttle HOT-433 Mainboard (2A4X5H21)", fixed menu items in PNP/PCI Configuration. It seems like FDC,COM, LPT ports not working with Rev 4 mainboard (PS/2 of course too). Maybe someone can fix it? Rev4 uses UM8886BF chipset and Rev 1-3 use UM8886AF. With AMIBIOS for rev1-3 and Rev4 FDC works fine, with Award 433WIE10 and BIOS from eSupport not.

One more Award BIOS, maybe someone have access to download it https://www.wimsbios.com/biosupdates/sh ... )/2A4X5H21