What are the two SOJ sockets next to the SIMM sockets for?

Video memory expansion

But there are also 2x empty SOJ sockets right next to the 2 soldered-on chips for th Cirrus video memory - that would make 6 chips total which is not a usual supported amount.

Are they, perhaps, for individual EDO soj chips in addition to the two SIMM slots?

This is a really weird board. What's with the funky placement of the barrel battery and the integrated video at the front end.

megatron-uk wrote on 2021-05-31, 12:24:

But there are also 2x empty SOJ sockets right next to the 2 soldered-on chips for th Cirrus video memory - that would make 6 chips total which is not a usual supported amount.

Are they, perhaps, for individual EDO soj chips in addition to the two SIMM slots?

That would be an absolute first. I'll see if I can find any documentation on a setup like that.

I'm seriously tempted by this board. I had VLB 486 back when they were new and it would fit a hole in my early Dos collection, right between a 386/486DLC and a high end AMD X5 486 PCI.

Anyone got any performance metrics out of one yet?

Damn. Seller doesn't like the UK as a shipping country ... and upon trying to contact the seller I get the message: "Unfortunately, this seller isn't able to respond to your question."

Looks like I'm out of luck for this one.

I actually got in touch with the seller and asked if they had specifically excluded the UK - since places such as Ireland and Guernsey were in the shipping list - they replied that they would amend the auction to include it.... well, they did amend the auction, but not to change the shipping locations; instead they jacked the price up by another $18.

The remaining units are now $106 + shipping, rather than $88, which makes it a bit less of a good deal since they all have some battery leakage to a lesser or greater extent.

GeneralDisorder wrote on 2021-05-30, 04:33:

I've got the board working with a DX4-100 at both 100 and 120 Mhz. Here's the jumpers - they match exactly as in the Biostar manual linked above. I have labeled the jumpers needed for CPU type setting. Note that pin 1 is towards the CPU socket for all of these jumpers.

Make SURE you get the settings right for your desired CPU. I made a mistake and burned out a trace on the back of the board - had to put in a bodge wire to fix it. Might have already been damaged by the leaking battery but be careful!

Have you tested onboard video? Did you get the VGA header for it? Would there be a MR.BIOS version by any chance for this board?

I'm just come back to this thread. I had a bunch of crap come up for the past several weeks, so I'm just now getting back to this board.

I think I either have a misconfiguration issue or my board or processor is dead.

Before checking back here, I read through all the silk screen on the board and tried to decipher the jumpers tonight. I set the board for 5V and 33Mhz clock speed, set up a power supply, connected a PC speaker and monitor, and . . . nothing.

No video signal, no POST beep, no smoke, no sparks, nothing. My Intel DX2 did get hot--uncomfortable to the touch actually and I confirmed with my multimeter that the board was supplying voltage to the BIOS battery connections.

viper32cm wrote on 2021-07-10, 03:55:

I'm just come back to this thread. I had a bunch of crap come up for the past several weeks, so I'm just now getting back to th […]
Show full quote

I'm just come back to this thread. I had a bunch of crap come up for the past several weeks, so I'm just now getting back to this board.

I think I either have a misconfiguration issue or my board or processor is dead.

Before checking back here, I read through all the silk screen on the board and tried to decipher the jumpers tonight. I set the board for 5V and 33Mhz clock speed, set up a power supply, connected a PC speaker and monitor, and . . . nothing.

No video signal, no POST beep, no smoke, no sparks, nothing. My Intel DX2 did get hot--uncomfortable to the touch actually and I confirmed with my multimeter that the board was supplying voltage to the BIOS battery connections.

I was having the exact same results after removing the leaky battery. Turns out the corrosion had indeed damaged a few traces. This was my first board repair so I had to attach some ugly bodge wires but after doing so it finally worked.

I successfully booted using a CX486DX2 66 and an AM486DX2 66 using the jumper settings from the related (as per the BIOS string) board posted here previously.

After some tinkering I managed to run an AM586 at the proper 133MHz (still shows up as a 100MHz Enhanced DX4 at the boot screen) using the jumper settings from this page: http://www.lejabeach.com/Biostar/MB-14Series/ … TAR_1433uiv.htm
Turns out JP20 was the key to getting the correct 4x multiplier (was previously only managing a 3x multiplier)

I also tried booting with a TI486DX4-100 and an IBM 5x86-3V3 100HF but no dice: either froze or boot-looped at the post screen.

Attached are some pictures from the AM586, its jumper settings, and the Motherboard and the included accessories. I got it from the ebay seller posted here. If you're thinking about getting one do keep in mind that the board may need some repair from the corrosion.

This is my first post, and I'm not very well versed software-wise, but if there's any suggestions, tests or benches you'd like me to run, please do tell.

Cheers,
-RetroPC5x86

retropc5x86 wrote on 2021-08-03, 02:58:

I was having the exact same results after removing the leaky battery. Turns out the corrosion had indeed damaged a few traces. This was my first board repair so I had to attach some ugly bodge wires but after doing so it finally worked.
* * * *
This is my first post, and I'm not very well versed software-wise, but if there's any suggestions, tests or benches you'd like me to run, please do tell.

I've been on this board for three years, and your way ahead of me with your first post 😀. How many bodge wires did you have to do? I see the one on the photo on the top side of the board.

I'd bet that I have same problem with my board that you had. I just don't have the time or (if I'm being honest) the experience/skill to do those types of repairs.

viper32cm wrote on 2021-08-07, 04:28:

retropc5x86 wrote on 2021-08-03, 02:58:

I was having the exact same results after removing the leaky battery. Turns out the corrosion had indeed damaged a few traces. This was my first board repair so I had to attach some ugly bodge wires but after doing so it finally worked.
* * * *
This is my first post, and I'm not very well versed software-wise, but if there's any suggestions, tests or benches you'd like me to run, please do tell.

I've been on this board for three years, and your way ahead of me with your first post 😀. How many bodge wires did you have to do? I see the one on the photo on the top side of the board.

I'd bet that I have same problem with my board that you had. I just don't have the time or (if I'm being honest) the experience/skill to do those types of repairs.

Originally I fixed 4 traces: 3 (white, green, yellow) via bodge wires and 1 applying solder over the broken trace. Then I blew another one (red), magic smoke and all, by placing the processor in the wrong orientation (yep, yikes). And regarding skill, I say go for it if you have the time, my first soldering fixes were atrocious, and my current ones still leave a lot to be desired -as the attached picture demonstrates- but they get the job done; and the feeling of fixing something is quite satisfying.

Thanks! Those budges look consistent with what I think is wrong with mine. I knew I shouldn't have bought a motherboard with a barrel battery.

Hey, sometimes you gotta have flying wires.
My Alaris Leopard's got a couple, one of which was necessitated after a Varta bomb blast. (I also had to reflow some of the pins on the 82C206 chip and replace some ailing TTLs to make the L2 cache work reliably.)

Anyway that Techmedia board looks to be a pretty solid performer, gotta love that feisty UMC UM8498F chipset.

After a couple more tries I managed to boot with the TI486DX4-100 using the exact same jumper settings printed on the board (for a CX486DX2).
The IBM 5x86 is still a no-go. I'm leaning towards the BIOS not being compatible, even more so after looking at this compatibility list from Cyrix:
https://web.archive.org/web/19961221092122/ht … 86/5x-mblst.htm
It says the Biostar MB-1433 UIV board should support the 5x86 as long as it has the AMI 7/24/95 BIOS; but my board has a BIOS dated 7/25/94.
I've looked for the updated BIOS online but haven't find it so far.
So if anyone has an MB-1425/33/40/50 UIV Rev.7 board with the AMI 7/24/95 BIOS, please dump it.

@retropc5x86: can you dump your bios to possibly resurrect a vanilla UIV (without onboard video) board?

7/24/95 : that is a typo, there is no such core version. 071595 is the next one. I'll have a look if I can find a MR bios for this board, that might do the trick too.

evasive wrote on 2022-01-06, 08:50:

@retropc5x86: can you dump your bios to possibly resurrect a vanilla UIV (without onboard video) board?

7/24/95 : that is a typo, there is no such core version. 071595 is the next one. I'll have a look if I can find a MR bios for this board, that might do the trick too.

There you go. I changed the extension to .txt since it wouldn't let me upload it with the default .dmp (or at least that's the default extension given by the bios dump utility I used: Matthias Bokelkamp's BIOS utility)

It's my first time dumping a BIOS, so let me know if the file works or if you need me to use some software/utility in particular.

Ok, that is the same we have for it on the page:
https://www.ultimateretro.net/en/motherboards/8470

As you can see I have added your pictures in there as well.

That reference page definitely has typo errors. This bios core version should do the trick. However, there's another thing in there:

Biostar MB1433UIV Rev. 7

that is a hardware revision. The UIV comes in several hardware revisions and I fear this board is not on the Rev.7 level for the hardware used...

Ohhh im no the only one that bought this board, doh i did give up after few test runs trying to get a DX2ODPR66 overdrive working.

I did socket it right 😉 at least what i remember but it seems that others ended up burning the same trace as the attached images.
At least what i can see its the same on @GeneralDisorder and @retropc5x86 pictures.

Does any one know where it was suppost to go to?

I currently running the board with a cyrix dx2 66 mhz.

Hope it is ok i stole the picture to mark.