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Help for Motherboard id

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First post, by Carstenl

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Hi,

I´am new to the forum, and this is my first post.

I need some help to find the jumper settings for this MB, i have been looking around on the
different MB sites, but i have not been able to find anything about this board !!.

First i thought it was a FIC, but it does not not match any FIC board.

I am not sure that the jumpers are set to 486 dx/4 as the label on the board shows, so
i dont dare to put in a cpu to test it.

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Reply 1 of 27, by evasive

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I have literally nothing that matches the 3 VLB/3PCI layout. Not with any chipset.

I think a bios dump (or if we are lucky, ANY markings in the backside of the board) will be our only chance to ID this thing.

Reply 2 of 27, by Horun

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IIRC someone last summer had the same board and posted questions about it but cannot find the topic. The silkscreen 486 V.I.P. rev is definitely something I remember and but cannot recall the details....

Hate posting a reply and have to edit it because it made no sense 😁 First computer was an IBM 3270 workstation with CGA monitor. 🤣 Second computer a 286 12Mhz with real IDE drive ! After that came 386, 486, Pentium, P.Pro and everything after....

Reply 3 of 27, by Carstenl

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Hi,

Thanks for your answers, it is really a hard one to crack.
Perhaps the person that posted about the board last summer, has sold it to me 😀
I have uploaded a picture of backside of the board, but there is not much info on it.
There is no information on the last Isa slot ( only a sticker with year, month and serial number )

Question.: how to make a bios dump, when i can get i to work ?.
Can i read the bios chip with a eprom reader ?, because i think that my brother has got one.
The bios chip is Eeprom, i could see that after i lifted the sticker from it.

Regards
Carsten

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Reply 4 of 27, by majestyk

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Looks like an EPROM to me.

The board and it´s kind of making reminds me of a (little later) Gigabyte board on amoretro:
http://www.amoretro.de/2012/02/gigabyte-ga-54 … rd-486-pci.html

And I have never seen a silly sticker saying "Only error cpu types causes it damaged".

Reply 6 of 27, by computerguy08

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If you can get the board to boot, try GETROM
http://cd.textfiles.com/microhaus/mhblackbox3 … MORY/GETROM.ZIP

Another good alternative is to use an EPROM reader (like the TL866), that works just as well.

Looking for a motherboard? You can find it in Ultimate Hardware 2019: http://www.win3x.org/uh19/motherboard/search
Join our UH19 Discord server here: https://discord.gg/HWWH7hsk2p

Reply 7 of 27, by dionb

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Not sure you're going to find much info on the specific board in the BIOS, MR BIOS images tended to be generic per chipset.

Reverse-engineering jumpers can be quite fun, although late 486 boards like this are of course the most challenging with their sheer number of jumper. Good news here is that the jumpers seem clearly separated into separate functional groups, particularly those around the VRM. Bad news is that some groups seem to be missing jumper caps entirely (the set down by the VLB slots). Not having a known-functional setup doesn't help...

As for that asinine warning: turn it around. Consider what can actually damage a CPU and avoid that. Then you're safe to try all other combinations. Basically only overvolting can actually damage a CPU. Fortunately voltage is something you can easily measure (if you have a multimeter). Fire up the board without CPU and measure voltage between Vcc and GND pins in the socket. 3.3V: safe for that DX4 as per sticker. 5V: not safe for DX4, stick in an older 5V part.

Ideal test CPU would probably be an Am5x86-133 as they can tolerate 3V-5V for short periods and most will run at 3x50MHz so will at least boot if you accidentally set bus speed to 50MHz (assuming you didn't set the multiplier to 4x, as 200MHz working is definitely not a given). Also the Am5x86 supports WB caching, but (unlike Cx5x86) will happily run with same simple settings as i486SX/DX. Second choice would be an i486DX-50 (not DX/2), again because of 50MHz bus speed.

Apart from a known-good test CPU you also want a single, known-good FP SIMM and a known-good ISA VGA card. PCI might work. A VLB card is also useful, but given those missing jumper caps, I'd first want to confirm everything works with ISA before messing around with VLB.

Reply 8 of 27, by Deksor

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Can you make better photos so we can put them in UH19 ? (http://www.win3x.org/uh19/) Your photos are mostly fine, but taking them under a light casts your shadow and makes some parts of the PCB too shiny.

As for the bios, it's a Phoenix bios, not a MR.Bios ^^. The MR.Bios part is the keyboard controller. Unfortunately in my experience Phoenix bios aren't really useful for identifying boards (unless someone knows a specific trick for Phoenix bios that we haven't seen yet ?)

Trying to identify old hardware ? Visit Ultimate Hardware 2019 - Project's thread The Ultimate Hardware 2019 (UH19) project- a stason.org/TH99
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Reply 9 of 27, by Carstenl

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Thanks for your help,

I will try to measure the voltage between the pins, and see what i get.
I have foundt this scheme. http://ps-2.kev009.com/eprmhtml/eprmx/h12203.htm

I have bought one of these "pc analyzer cards " from China, it is both PCI and ISA. Perhaps it would be a good idea to plug it in
when I have found out what kind of cpu i can plug into the board.

I will take some new photos and upload them to UH19.

Thanks for your help 😀.

Regards.
Carsten

Reply 11 of 27, by Carstenl

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I have now tested with 2 486- 50 Mhz cpu´s , but i get no life in it. !!
I have tested the cpu´s before and after i have installed them in the board, so i know that they are working.

Also installed the " PC analyzer card " in both ISA and PCI slot, but i get no codes in the display ( see picture )
Perhaps I only can the the board to work if i have the right jumper settings, or perhaps the board is not working....

I have tested the "PC analyzer card" on another board, and the card works just fine ( nice tool )

Regards
Carsten

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Reply 13 of 27, by Carstenl

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Hi,

I have used an external battery on the 4-pin connector next to the Diode´s, but you can not see it on the last picture
I have connected the battery so that pin 1 is plus and pin 4 is minus. I have used a 3,6 volt lithium battery ( almost new )

Regards
Carsten

Reply 15 of 27, by weedeewee

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Just a guess !!

When you put power on the mainboard, does the bios chip get warm?
It might be a long shot, but most of the time all the chips have the same orientation for pin one, yet the bios is turned the other way.
You could take it out, verify if the orientation matches, and if wrong, find yourself another bios chip and bios code to program it and replace the burnt one.

fyi, the bios chip, the one that has the phoenix label on it.

Reply 16 of 27, by Carstenl

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Hi,

Have have used a 1mb module, and i have placed it in each of the 30-pin sockets.
I havealso tried a 4mb module in each of the 72 pin sockets.

Thanks for the long shot, you are just great 😀... it turns out that the bios chip was turned the wrong way around 🙁.
I did not see that when i got the board, and i have newer seen it before. Perhaps somebody tried to get it to work
and turned the chip the wrong way by mistake - who knows ?.
That´s proberly why the cache chips has been removed,

You can se the that some of the wires is burned.

Now the big question...where to get a new bios chip ?.
I think it is the same type that is on this board http://www.amoretro.de/2012/09/qdi-mp4-p4u885 … otherboard.html

Regards
Carsten

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Reply 17 of 27, by Vynix

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For the BIOS you should need a 27Cxxx [where "xxx" is the capacity of the EPROM, such as 27C256, 27C512...] EPROM (or equivalent, there should be a model number written on it), something to flash it (either a dedicated programmer [the safest option], a NIC with a EPROM socket, or the risky "hotswap flash" method), and a BIOS to flash onto the EPROM.

For the BIOS, you could try to find a BIOS that is programmed for a motherboard with an identical chipset, in your instance, the BIOS from a MSI MS-4134 PCI/VLB board should work (I don't think 486 BIOSes were that advanced back then) as it shares the same ALi M1435/M1429 chipset combo.

Proud owner of a Shuttle HOT-555A 430VX motherboard and two wonderful retro laptops, namely a Compaq Armada 1700 [nonfunctional] and a HP Omnibook XE3-GC [fully working :p]

Reply 18 of 27, by majestyk

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I´m not so sure if the hotswapping method or flashing in a NIC will work with an EPROM that needs to be erased first with ultraviolet radiation.
Unused EPROMS (without programming) can hardly be found today.
And as far as I remember not every programmer is capable of programming EPROMS.

Reply 19 of 27, by Vynix

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Yeah - forgot to mention that. The EPROM needs to be blanked first (I dunno why I omitted this).

Proud owner of a Shuttle HOT-555A 430VX motherboard and two wonderful retro laptops, namely a Compaq Armada 1700 [nonfunctional] and a HP Omnibook XE3-GC [fully working :p]