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Am5x86 on UM8810P

DonutKing

Experienced Member
Joined
Mar 24, 2011
Messages
96
Location
Gold Coast, Australia
I have an ECS UM8810P-AIO rev 1.1 which I'm trying to use with an Am5x86-133. I have seen other people using this combo on the internet before but I'm not having any luck.

The board won't recognise the CPU. Comes up as '??? 100MHz'. It will boot with an ADZ stepping CPU but it seems quite unstable. It won't boot at all with a BDC stepping, yet its fine with a DX2/66. I've tried jumper settings for 486DX4 and Am486DXL but no luck.

Here's the jumper settings http://stason.org/TULARC/pc/motherboards/E/ELITEGROUP-COMPUTER-SYSTEMS-INC-486-UM8810P-AIO.html
My board does have the voltage regulator and I've set it to 3.45V according to the silk-screened info on the board.

Should I be using a different CPU type?


I have managed to find a BIOS on the internet, version 32J dated december 1996 (my current version is dated november 1994). However the BIOS chip on my board is of type 27C010A-15 which I believe is NOT a flash EPROM. Interestingly, according to the above link there is a jumper setting for 5V/12V flash EPROM, and these jumpers are open on my board.

So I'm a bit confused. Is it possible to flash this BIOS, or will I need to get it UV erased and reprogrammed?
 

joekster

Experienced Member
Joined
Jul 25, 2009
Messages
273
Location
Palm Beach, Florida
Well, I don't have this exact board, but I've worked with many UMC-8810 / AMD5x83-133 combos before. Based on your results, it sounds like a bios issue. According to the jumper link you provided, the board supports eprom and flash bios chips - it sounds like yours came with an eprom :( . I would get another eprom of the same kind (dont erase yours - just in case), and program it with the updated bios. You may be able to swap in a flash chip, but there may be a reason they used an eprom - like missing support logic for flash???

Have you tried a different bus speed (25 or 40mhz)? maybe the current bios is confused as to which chip is installed...
 

DonutKing

Experienced Member
Joined
Mar 24, 2011
Messages
96
Location
Gold Coast, Australia
yeah different bus speeds don't make any difference.
What CPU type did you set your jumpers for?

I don't know anyone with an EPROM programmer. I've just bought a couple of AM28F010A chips so I'll try hotswapping and flashing and see how it goes.
 

twolazy

Veteran Member
Joined
May 22, 2011
Messages
1,600
Location
Chicago, IL
I would not recommend hot swapping. If it did not work the first few times, its possible you could destroy your working 27c rom, or worse the motherboard! Eproms were never designed to be removed and reinserted more the a few times. I suggest the following method...

You can flash the 28F on alot of different pci/isa network cards, that are dirt cheap! Chances are you already own a few, or in my case a buttload LOL! Look for Intel pro 100's or 3com 905B's, as well as cheapy realtek pci cards. These usually come with a dip socket, and can easily flash the 28F flash eprom with uniflash+. After you get it programmed, make sure to double check the voltage on the motherboard eprom socket. If all looks good, and the voltage is within specs of the 28F, just insert it, its pin compatible for read, just not writing. Shame you do not live in the USA, I could help you if you did, I think snail mail be a long wait going across the pond. :(

http://www.rainbow-software.org/uniflash/


BTW, You could in theory place the 27c outside for 4-7 days in the sunlight and it will erase the entire chip if the see through window is left uncovered...
 
Last edited:

DonutKing

Experienced Member
Joined
Mar 24, 2011
Messages
96
Location
Gold Coast, Australia
Just a bit of a bump... I did manage to get this to work...

I bought a G540 USB programmer off ebay, its cheap and nasty but does the job. This was primarily for some other projects but it came in handy for this too...

The flash EPROMs I ordered never turned up :(

But I did find a dead Socket 7 motherboard with a W29C020C flash EPROM on it for a donor.

So the first problem was that the 29C020C is a 2Mbit chip, while the 27C010 that was in the board is only 1Mbit.

That's easily solved by making appending copy of the BIOS binary file to itself with this command:
copy /b 8810w32j.bin + 8810w32j.bin 8810bios.bin

This way, the 1Mbit BIOS can be programmed into the 2MBit chip.

Once that's done and installed in the motherboard, I set the jumpers for 'SL-DX/2/4', with JP29 shorted (this controls the multiplier) and JP31 set to 3-4 to set the voltage. JP34 isn't marked clearly because there's 2 caps right next to it but these jumpers go in the same direction as neighbouring JP29.

Once these are all set, on boot I was greeted with 'AM5x86-133MHz-P75' :)

Seems to be running great now. The new BIOS recognises the 5x86 :)

Here's the bios file if somebody happens to come across this and is trying to do the same thing: http://dl.dropbox.com/u/9151127/8810AIO.32J
 
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