Is that a v2 board Garrett?

There is a large date range variance in v2 boards. I wonder if it is related to certain date codes of the UMC chipset... might help if everyone experiencing the issue uploaded photos of their 8881/8886 chips.

Does the issue also occur when using a KVM?

Here a photo of the board. The issue also occured with KVM. My feeling always was that it is more a keyboard issue than a mouse issue because, for example, a copy/paste action in Windows could be done with the mouse alone but as soon as I used a ctrl/insert key combination to 'pick up' a line the system froze. This board has an EEPROM with the original BIOS. And please ignore the rtc mod, the board behaved the same before the hack.

edit:
and testing was done with different cpu's, different RAM (EDO and FPM) and different psu's etc.

To improve the sampling data:
I have two of these boards.
No keyboard / mouse issues.

Feipoa made this board legendary.
The chipset is nice and fast, but a bit flaky - in my experience.
Still, Biostar did one of the better jobs with it.
It is surprising that people are experiencing such issues.

Chadti99 wrote on 2021-02-02, 15:16:

Is that a v2 board Garrett?

Yep.

v2 boards had chipsets dates from around mid-1995 to mid-1996. I normally use v2 and v3 boards with mid-1996 chipset dates, so I wonder if the issues you are experiencing are from these earlier 1995 era v2 boards. There are some PCB changes within the v2 versions alone, so maybe related?

“”

It is the UM8886BF southbridge chipset which is responsible for the keyboard and mouse controller. So far, the reports of mouse issues are coming from those who have a 1995 UM8886BF chipset, with "DYS". I personally have not used these older southbridge chipsets for extensive mouse/keyboard testing. Is there anyone with a newer chipset, preferably without the "DYS" that is experiencing these problems?

Talk about sick to the stomach... I just bought one of these motherboards (rev 2 with the UM8886BF southbridge) purely for the PS/2 port. I really hope I don't have the mouse/kb input problem... it should arrive next week. I'm so anxious now. It doesn't have DYS printed (it says FXS) but still I'm worried. I will come back to this thread once I get the board and tested things out.

Just a thought - does the kb/m issue happen to those running slower CPUs? I'll be running a 100mhz AMD.

edit: she's good! I had some weird mouse issues in Win 3.11 but that was only when I had ctmouse driver loaded as well. Without ctmouse the windows 3.11 ps/2 mouse option worked fine.

Happened to me with an AMD DX4/120, so yeah, probably.

You can always grab one of those Serial to PS2 adapters that have cropped up in recent years.

To whom it may concern, i'm playing with this motherboard once again, I can confirm that the UMC cpu works fine with the rev2 of the board using the Intel 486 DX/DX2 settings from Feipoa manual, also those settings apply for the Intel SX cpus.
That despite being unable to change RN11 from open to close

I also do have a question, what is going to happen if the 5v is used for lower cpu volt? I know there is a specific pin on the cpu which let the motherboard gives the right voltage, but not completely sure.

This is my board. It is a v2 with a 9622/9623 week dated chipset. Working fine with a Cx 5x86 for now, but I am still in the process of building the system so it's not really 'tested'.

It has a 04/10/1996 dated BIOS which may be of use to others here so I will dump and post it later tonight.

BIOS attached as promised.

So it looks like my MB-8433UUD-A system came together really nicely. Honestly, this is the fastest 486 I've ever seen (even if it may not be as fast as feopia's) once the 5x86 registers were enabled.

Now, it's time to add a Voodoo 1 to the MX86200 VGA card, install a Sound Blaster 16 and an MPU-401 MIDI Interface, and enjoy a shitload of DOS games.

(Part 1/2 due to 5 attachments limit)

The ALU speed is IMPRESSIVE. The FPU, not so much, but still..

Moreover, I can use Setmul to set the multiplier to 1x, which brings the system down to DX2-50 speeds. Perfect for Ultima VII and Theme Park.

And if I use Setmul to disable L1 cache, then it becomes basically a 386DX33.

I did not experiment with the motherboard's own Turbo button, which probably adds even more wait states and allows for further fine tuning. I will do that later.

(Part 2/2 due to 5 attachments limit)

That's impressive!
I bought the same motherboard earlier this year, it came with an AMD 486 DX4-100, maybe I should start playing around with it 😀

appiah4 wrote on 2021-04-15, 13:30:

This is my board. It is a v2 with a 9622/9623 week dated chipset. Working fine with a Cx 5x86 for now, but I am still in the process of building the system so it's not really 'tested'.

It has a 04/10/1996 dated BIOS which may be of use to others here so I will dump and post it later tonight.

My motherboard is just like yours, just a bit older (95 date code), do you have a umc cpu to try by any chance?

Have you enabled the special features yet? The FPU enhancement is one of the big ones.

If you plan on using a Voodoo1 or Voodoo2, this thread should offer some insight as to what speed you can expect. Voodoo 1 vs. Voodoo 2 on a 486

Nemo1985 wrote on 2021-04-16, 21:46:

My motherboard is just like yours, just a bit older (95 date code), do you have a umc cpu to try by any chance?

I have a UMC U5S-33, do you want me to try it? I don't see why it wouldn't run, UH19 has an MTL jumper setting document with U5S listed there, have you tried these?

http://www.win3x.org/uh19/public/motherboard/ … anual/33492.pdf

feipoa wrote on 2021-04-17, 05:43:

Have you enabled the special features yet? The FPU enhancement is one of the big ones.

If you plan on using a Voodoo1 or Voodoo2, this thread should offer some insight as to what speed you can expect. Voodoo 1 vs. Voodoo 2 on a 486

Yes, I did, and the performance appears to be slightly ahead of a Pentium 90 in NSSI after the enhancements.

I also installed a Voodoo 1 and tested it with Tomb Raider 3dfx demo, it works quite well (not sure about framerate though - is there a way to enable that in the demo?)

I will look into that thread for Voodoo 2 info. I doubt it would be a meaningful upgrade though, particularly not for me as I won't install Win9x on this (DOS and OS/2 only)

appiah4 wrote on 2021-04-17, 07:24:

Nemo1985 wrote on 2021-04-16, 21:46:

My motherboard is just like yours, just a bit older (95 date code), do you have a umc cpu to try by any chance?

I have a UMC U5S-33, do you want me to try it? I don't see why it wouldn't run, UH19 has an MTL jumper setting document with U5S listed there, have you tried these?

http://www.win3x.org/uh19/public/motherboard/ … anual/33492.pdf

On my motherboard it works fine, but according to the pdf made from Feipoa (which is better than common manual) says: RN11 is always open on MB-8433UUD versions 2 & 3. RN11 needs to be closed for U5S and U5SX.
And in fact it is open on our rev but still on mine mb works fine.