whitepawn wrote on 2021-03-13, 18:59:

Hi, I just bought a UMC graphics card which was very dirty.I cleaned it with removing dip socket chips. […]
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Hi,
I just bought a UMC graphics card which was very dirty.I cleaned it with removing dip socket chips.

After a careless moment UM23C256A (which i think is a BIOS chip) were inserted it in wrong direction and it let the magic smoke out.I cut power immediately but damage was done.Silly me, i am still mad at myself for this rookie mistake.

Anyway is there a bios file for this graphics card to burn a flash chip?

Here is card photo:

rsz_img_20210313_213512.jpg

Thanks for any help.

I guess you are going on the assumption that the UM23c256A is UMC's variant of a 23C256 mask ROM variant : https://www.alldatasheet.com/datasheet-pdf/pd … NEC/23C256.html and https://pdf1.alldatasheet.com/datasheet-pdf/v … TEK/23C256.html .

Assuming these two mask ROM chips have matching pinout, you could likely hazard to assume that the UM23c256A does too .

Now you need to

a) find a similar EPROM or EEPROM with a matching or easily adaptable pinout (EDIT NEC upd27256 might work) EDIT2: 28C256 EEPROM might work with some adaptations, according to this : https://electronics.stackexchange.com/questio … -how-to-wire-we
b) Find a compatible ROM dump (EDIT : See here http://www.vgamuseum.info/index.php/news/item … -umc-um85c408af )
c) Find a way to flash the EEPROM or EEPROM found in a) (and possibly a way to UV erase it if you are dealing with a non blank EPROM)
d) Adapt/switch the non matching pins, if any
e) Try it and hope nothing else is broken

EDIT :
Disclaimer : I am not an expert at this . Please careful check all this before trying and have someone experienced in this before proceeding to do anything based on my hunches/ideas/suggestions

Good job Darry ! I was just looking at vgamuseum and saw the similar but 512k card.
I do not have one but some one here has one nearly identical: questions about 2 graphic cards?
Maybe they could dump their bios...

Thank you both for your reply.
Since i don't have a eprom or eeprom programmer i have to use uniflash with hotflash method.I have some experience with XTIDE roms via this method.I don't have ant UV eraser also which leads me a flash chip (Intel 28F001BX-T) that i already have from a scrap PII mobo.

While digging internet i found this link: http://sbfmdrv.blogspot.com/2015/11/retrofitt … nto-old-pc.html Basicly it is about fitting 32 pin chip to 28 pin chip which leads flash capacity loss.In my case it is irrelevant because 128KB is way more bigger than UMC bios.I will try with this method tomorrow.

I have a friend which have a universal programmer.If above method will not work i will ask help from him.

Fail case:If 512k bios will not work i may solder new ram chips no problem.Inspected PCB also jumper shorts are different for ram configuration, this might also changed i believe.

No need a disclaimer, i am open to all suggestions.It is already dead, no big deal for me it was dirt cheap .

Have a nice weekend!