ivannudem wrote on 2021-01-30, 23:16:

Hi, i saw a 486 board on ebay which was teared down from a techmedia 486 machine. It got UMC um8498F chipsets on it. I asked the […]
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Hi, i saw a 486 board on ebay which was teared down from a techmedia 486 machine. It got UMC um8498F chipsets on it.
I asked the seller about several questions but he/she didn't have quite good knowledge of it.
I attached several photos of it in attachment
I would like to know:
1. Does it support EDO ram or only FPM ram because I need to buy separately from other seller, I don't want to make mistakes
2. It has jumpers for 3.45V, so I can plug in a Am5x86-133?
3. It has a nasty 3.6V barrel battery, I'd cut it off immediately if I buy it, is there any good replacement? Better yet, does this board offer separate CMOS external battery pins so that I could connect a non-rechargable battery pack? I couldn't see it near the barrel battery area.
4. If someone has the manual of this board or any knowledge of how to configure it, I'd like to know.
Thanks
Iván

I saw them back in December but the seller never answered the board model or any other good information: Re: Bought these (retro) hardware today
Searching for the board without clues to the manufacture was fruitless....

Thanks, Horun.
I read your post in the link you mentioned above, and I'm scared of the potentially leaky barrel battery... therefore I went away....

Is there an POST string in sight ?

Regarding the battery, the board looks fine to me. Now maybe the situation has worsened since the photo had been taken.

This is silkscreened under a sticker:

I've tried to research it, but can't find any information. Luckily the jumper settings are also silkscreened on the board.

Interestingly mine are from 1996. Imagine you bought this in 1996. It doesn't even have PCI slots, haha!

ivannudem wrote on 2021-01-30, 23:16:

3. It has a nasty 3.6V barrel battery, I'd cut it off immediately if I buy it, is there any good replacement? Better yet, does this board offer separate CMOS external battery pins so that I could connect a non-rechargable battery pack? I couldn't see it near the barrel battery area.

You can desolder it, like I have. The 3-pin barrel battery can still be easily found in most specialized components stores online, but I doubt that they still contain cadmium in the EU. I haven't noticed external battery pins on the board.

SpectriaForce wrote on 2021-02-25, 21:20:

This is silkscreened under a sticker: […]
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This is silkscreened under a sticker:

Markvision Flexboard socket 3 AT moederbord a.jpg

I've tried to research it, but can't find any information. Luckily the jumper settings are also silkscreened on the board.

Interestingly mine are from 1996. Imagine you bought this in 1996. It doesn't even have PCI slots, haha!

You bought one ? Does it work OK ? I was about to buy one until the response to a question was like "the pictures show everything you need to know", which is not always true. 😀

Horun wrote on 2021-02-26, 03:28:

SpectriaForce wrote on 2021-02-25, 21:20:

This is silkscreened under a sticker: […]
Show full quote

This is silkscreened under a sticker:

Markvision Flexboard socket 3 AT moederbord a.jpg

I've tried to research it, but can't find any information. Luckily the jumper settings are also silkscreened on the board.

Interestingly mine are from 1996. Imagine you bought this in 1996. It doesn't even have PCI slots, haha!

You bought one ? Does it work OK ? I was about to buy one until the response to a question was like "the pictures show everything you need to know", which is not always true. 😀

I have two (for sale), they were installed in enclosures. They are new old stock and haven't tested them. I have no reason to believe that they don't work. You'll need to remove the leaking battery if you buy them from that American ebay seller. You'll also need the I/O ports, that might not be included if you buy loose elsewhere.

MarkVision is software from the printer maker LexMark. Other than that cannot find anything, I'm starting to think these were inside dedicated print server machines.

I also see some products sold under this brand mainly in Colombia and a few other South American countries.

TechMedia (techmedia.net) has disappeared in 1998.

A bios dump would help for the identification (as well as preservation of course). Now it must be a special one that contains also a video bios, but I think they're separated in the ROM.

I bought one of these recently with the i/o headers. The corrosion from the battery was no big deal. I'm awaiting a 486 CPU to give it a test. Has anyone had any luck getting a system based on this board to run?

Nope, otherwise we would have a bios string already and possibly an ID.

evasive wrote on 2021-05-12, 16:18:

Nope, otherwise we would have a bios string already and possibly an ID.

Alright, I'll see what I can do. My 486 CPU arrives next week.

Thanks in advance for your efforts

I bought several of these NOS motherboards and have one running at the moment. They have built in 1mb Cirrus Logic VLB video that's not bad - has VESA support. The cache is small at 128k but the sockets and jumpers are there for up to 1mb. I've got most of the jumpers figured out except for the bus multiplier.... played around with some of the unknown jumpers and nothing changed the reported speed when powered on. Although I am running a 5x86 133 in it at the moment which may be defeating the bus multiplier with it's internal locked 4x. The POST reports 100mhz but CPU identification software reports 133.

There was some battery leakage that I had to clean up and replaced the NiCd with a NiMH but no actual damage to this first board. Haven't opened the second one yet.

Pretty good deal for the price being NOS. 3D Bench turns in 56.7 with the 5x86 using the on-board video. I expect that to improve a bit with added cache.

BIOS string: 40-P301-001223-00101111-072594-UMC498-H

GD

BIOS string says Biostar MB-14xxUIV
http://www.win3x.org/uh19/motherboard/show/1091

which has 3 VLB connectors, not 2. So your NOS board has had its bios swapped for another already.

One of the VLB's is taken up by the onboard Cirrus Logic 1mb video, and one of the ISA's is taken up by an onboard IDE and multi-I/O interface. Different board layout but it looks like a lot of the jumpers are numbered the same so the manual for that Biostar looks to be quite useful. I shall spend some time trying out settings and hopefully get all the jumpers documented. The only thing not printed on the board is a complete cpu type selection and the jumper numbers and number of pins appear the same just in different locations.

These boards were built for Techmedia to be sold as barebones systems. The current seller pulled the 486 boards out of the systems and sells the cases separate or with Pentium MMX boards. They don't have any information on the jumpers or any manuals for the 486 boards but having talked to them back and forth a bit I can say for certain that they didn't swap any BIOS chips. They don't have the sophistication for that.

GD

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!

If anyone wants one - there's a few more available I'm told:

https://www.ebay.com/itm/324479097911

GD

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!

If you are sure of that I'll mention it on the page. It is a pity we can't really slap a MB-14**XYZ label on it yet, but good to know it's a Biostar board.

page in UH19:
http://www.win3x.org/uh19/motherboard/show/8470