Vogons has a BIOS section both in forums and in Vogons drivers Library. I would look through the 80486 BIOS Image collection in forums first.
80486 BIOS image collection
I would try one of these BIOS, all use same chipset (the UMC and BioteQ are same):
#3 "unknown" MB-4D33/50NR Re: 80486 BIOS image collection
#42 Chicony CH-491E Re: 80486 BIOS image collection
#45 Peacock UC 4913 Re: 80486 BIOS image collection
#66 Mitac IH4077C Re: 80486 BIOS image collection <one of my boards and very similar to yours)
#: 104 Peacock / ECS UC4913 REV:1.0 Re: 80486 BIOS image collection
or this
Biostar MB-1433UCV / 1450UCV https://www.philscomputerlab.com/biostar-mb-1433.html

Edit:
layout is near identical to the Mitac IH4077 but not a rev C. Maybe a first rev???
Yours has a crystal so is locked to that, is why the jumpers Jp4, jp5 and jp6 are missing (those are for if the MX clock IC is installed as in the IH4077C)

The AMI BIOS post but go in loop (Biostar MB-1433UCV / 1450UCV)
Mitac IH4077C is good but have the same issue whit other AWARD BIOS ,
HDD is not recognized whit controller different from GOLDSTAR

in pic how is recognized a 128MB 984-16-16

Is that 128mb a CF card ? If so you need to enter the Drive 984 cyl, 16 head, 16 sector manually. Most older boards cannot auto detect a CF properly afaik.

I thought the same thing, and I just entered the values the result and stat that did not start, I ran the command FDISK / mbr from the floppy and the result was null
FDISK tells me that there are no partitions and that I cannot create any.

This board looks almost identical to yours : https://www.ultimateretro.net/en/motherboards/6638 (maybe it's the same with a different rev ?)

And there are two BIOS images available for it 😁

I downloaded the two bios, but I don't think I've tested them. I'll give it one more try

Hi, I have now read about this HD detection problem, I think it is a BIOS problem, but even if it was the problem it could still be solved without updating.
First I tell you I had the same problem with a similar MB (UMC chipset) and AMI BIOS, same manufacturer but 386DX CPU and ISA Slot.
I solved the problem, but I had to try other controllers, the first thing to do is to understand if the PC boots correctly (and therefore the BIOS works).
So try booting without HD, from bootable floppy.
If it works you should try to boot from HD, in that case I suggest you always boot from bootable floppy, then from DOS you try to go to c: \, at which point you have to see if it goes or does not find it.
So see if you can do these tests and then let's see what to do next.
Greetings

It is the procedure that I used to do the tests but in the end I decided to buy this card and hope that the bios is 100% compatible

dataino.it wrote on 2021-11-26, 14:05:

It is the procedure that I used to do the tests but in the end I decided to buy this card and hope that the bios is 100% compatible

Okay I thought you wanted to solve the problem, but in this case if that BIOS is okay, you will end up with two working motherboards.
It is possible that the BIOS are very similar, you have to try the other card and see what happens, if you have the same problem, you have to try several times until everything works.
That is, if it works in one PC, it does not necessarily work in the other, even if it should, it may happen that it does not work, at which point you have to understand if it is the motherboard or the controller.

In the end I have two working cards ... but with the same limitation .. with some isa controllers they do not recognize the CF correctly in the next few days I try with a physical HDD and a VLB controller, just to understand.

Oh well this is probably a cosmetic bug.
Your HDD is ~4GB, right ?

Jan Steunebrink just wrote how to fix it here :
Re: Diy modding support for k6+And 120gb hard drives into bios roms
You don't actually need to fix it to get your hdd working, it should already work. I have the same problem on my SiS 471G motherboard. The value is having an overflow for anything over 2GB. So the value displayed in the BIOS is the capacity %2048.

But the value is actually correct inside the bios. If you format the hdd, you'll have full access to the 4GB (up to 8GB).

Is a 128MB CF .. that is recognized with the same controller from other mobo ... 286,386,486

Strange. What is actually your problem then ?
I calculated the amount of MB by doing (33752 * 16 *16 * 512) / (1024 * 1024) = 4219MB.

4219 % 2048 = 123

I wonder why it reports 33752 cylinders then if that's wrong.

The problem is that it did not automatically recognize the HDD capacity, but even if I manually set the values in the bios, the system starts from the floppy but then does not see the existing partitions and does not create any even if the CF has been cleared. Only by using a "GOLDSTAR" controller can the situation be resolved

dataino.it wrote on 2021-11-28, 22:59:

The problem is that it did not automatically recognize the HDD capacity, but even if I manually set the values in the bios, the system starts from the floppy but then does not see the existing partitions and does not create any even if the CF has been cleared. Only by using a "GOLDSTAR" controller can the situation be resolved

Hi I with a 128MB CF I had the same problem, ditto with three other 256MB, according to some they could not be recognized and bla bla bla, currently I have them on various old PCs, from 386SX to various 486 and Pentium, not I managed to put them on the 286 because the power supply failed, however it is a problem both of the BIOS and of the controller cards, the BIOS one can be overcome by manually entering the values, the one of the controller instead if it does not work you have to find another one that functions.
I asked you if starting from floppy, you saw the C: \ disk, if you see ok it is not difficult to make it bootable, if you do not see it that is it says: drive not found (or similar), you have to guess the values ​​to insert in the BIOS, if you want you could try these: cyln245 hd2 Sec32 Size8MB, even if they are much lower it doesn't matter, so when you do fdisk it will detect the right capacity of the CF (in that case about 123MB).