Nice work! Pretty standard looking vlb board, someone's taken the vga card, etc but that's no big deal. 50% of the boards I find from that era have acid damage but I can't see a battery there at all? Hopefully there's an external battery header to make things easy on you.

Biostar? I see Bioteq on the stickers.

I have that exact board. It's a Biostar MB-1433UCV.

There is no battery to leak... it instead has a Dallas-clone RTC chip. Unfortunately it's soldered-on, and it's right in front of the ISA slots so you can't get in there to modify the chip for an external battery without removing it from the board.

NitroX infinity wrote:

Biostar? I see Bioteq on the stickers.

Bioteq is Biostar 😉... I think it's still called 'Bioteq Technologies' in China, but it's known as Biostar everywhere else. The quality of their boards used to be a bit iffy some years ago, but now they're quite competitive when it comes to budget, mainstream and enthusiast boards (my main Ivy gaming rig is using a Biostar board and it's been perfect 😀).

More images!

Hopefully I can fire it up tonight. Don't have a VLB graphics card, so ISA will have to do for now.

http://imgur.com/a/MGpJD

And the controller card:

http://i.imgur.com/j7RHv9f.jpg

You can just use a normal ISA graphics in it.. You dont have to use a special VLB graphics card to get display only..

VLB cards are only a lot faster..

Ran into a roadblock: I don't have any RAM that fits 😀

The memory from the Acer 486 is a lot longer. Oh well I will source some Ram then.

Also I didn't find any jumpers for voltage or multiplier and I'm worried that this board is too old for DX4 chips...

And the controller card:

Huh... not only do you have the exact same motherboard I do, but you also have the exact same I/O controller.

The board takes 30 pin SIMMs... common for a 486, but certainly a bit inconvenient if you don't happen to have any. When you're hunting some down, remember they have to be installed in fours.

It is a 5V-only board, but that doesn't rule out a DX4 if you really want one. You'd need either an interposer adapter or an Intel DX4 Overdrive chip.

Old thread, yes, but I just acquired the same board; mine is ver. 1.

I'm having issues getting a DX2 66Mhz running on it; I follow the jumper settings from http://museum.ttrk.ee/th99/m/A-B/32868.htm but the system just beeps 7 times, pause, repeat. It did boot with a DX 40; the Dallas clone needs to be replaced; already have a dip socket and a DS12887A to replace it.

Mau1wurf1977 -- have you been able to get your board up and running with a DX2 66Mhz? If so, what are your jumper settings?

Hudson187 wrote:

Old thread, yes, but I just acquired the same board; mine is ver. 1.

I'm having issues getting a DX2 66Mhz running on it; I follow the jumper settings from http://museum.ttrk.ee/th99/m/A-B/32868.htm but the system just beeps 7 times, pause, repeat. It did boot with a DX 40; the Dallas clone needs to be replaced; already have a dip socket and a DS12887A to replace it.

Mau1wurf1977 -- have you been able to get your board up and running with a DX2 66Mhz? If so, what are your jumper settings?

Hi!

I eventually got around to replacing the RTC with a socket and Dallas. It then posted fine.

I went over all the jumpers and the board worked well with a SX-25 and DX-33:

Ultima 7 on this board with a SX-25:

http://www.youtube.com/watch?v=ATnFjs9giMo

Ultima 7 on this board with a DX-33:

http://www.youtube.com/watch?v=cDK-D8YbWOk

I don't have any decent VLB cards, the one I have is slower than an ISA ET4000 😀

I didn't try a DX2, seeing the jumpers don't support one (at least on my board) and only having 5V I didn't even try. Also while I do have two DX2 chips, I don't know what type they are as they have a heatsink from Krypton attached to it.

I tried 2 DX2 66Mhz, both resulted with the same 7 short beep. According to the internets, AMI Bios 7 beeps mean "Virtual mode exception error: CPU has generated an exception error; bad CPU or motherboard". I know the CPUs are good and the motherboard is fine; it boots with a 40Mhz DX. All info I've found on this board say it does support DX2 @ 66, but the jumper settings do not seem to work properly. I'm wondering if my board won't support it without a bios update; thing is, I cannot find ANY bios downloads for this board. It is now become my mission to try and get this board to support DX2 @ 66Mhz. I may call Biostar tomorrow to speak with someone to see if they have bios available somewhere in their archives.

So get this; turns out I have a 2nd board in storage! I pulled it out; its a newer rev, same model -- I installed the same DX2 66Mhz and memory from the issue board, set the jumpers, powered it on and it booted! Here is the kicker; I got the "LOW CMOS BATT" error... I then turned the system off, then back on and that board started with the 7 short beeps -- I'm starting to think it has something to do with the bad Dallas clone; I'm going to replace both tomorrow and see what happens.

Yes I had weird behaviours on boards without working RTC. This board also did something weird. Can't remember what it was though. Issue went away after the RTC fix.

I was able to replace the RTC and she booted up fine with a DX2 66Mhz. I've started to build the system, but now have ran into a few issues; what I've done thus far:

1 ) Replaced the RTC
2 ) Installed a 486DX2 66Mhz -- boots fine
3 ) Replaced all cache memory with 15ns 256k chips; booted and read 256k cache
4 ) Installed 4x 4mb memory modules, booted fine and read 16mb
5 ) Installed VLB video and IDE controller, along with MQX midi card, GUS Classic and SBPro2; system did not boot.
6 ) Removed all cards but video, system booted, but video was garbled.
7 ) Unplugged power, re-plugged then powered on, system booted fine.
8 ) Installed VLB IDE controller, system booted, but video was "colorful"
9 ) Installed a different VLB IDE controller, results same thing as 8
10 ) Installed different VLB video card, results same as 8

That's when I stopped working on it -- had to go to bed. This is what I'd like to check:

1) Bus speed -- make sure its on 33Mhz

Questions/concerns:

Bad memory, either system or cache?
Board can't handle more than 1 VLB card?
Board doesn't like DX2 66?

I'm not stumped quite yet, but I don't have much free time in the next few weeks and would really like to get this system stable soon!

I think it maybe could be the ISA connection.. I had also had problems with non good working cards.. I cleaned up the ISA connectors on the card and working again..
And sometimes to problems relays on the ISA sockets.. Maybe the pins are corridated, or the VLB slots is mis-used and worn out.

Dumped the BIOS today, in case someone ever needs it.

Thanks for that 😀

This board was my first 486 motherboard, bought second hand back in 1998. Runs a 486DX2 66 wonderfully. I have a huge sentimental attachment to this board - really got me into computers back then and I've been stuck ever since!

Still have it too!