Hi Everyone,
I'm diving into a project that is a little above my head and could really use some guidance.
So, I have a bunch of late 90's proprietary motherboards for a custom control system that is no longer supported. The problem with all these units is that the battery for the BIOS has died and the boards will no longer boot.
Now, I have ONE motherboard with BIOS that is still alive. I would like to read the chip and clone the BIOS to the bad motherboards to get them working again.
The chip that contains the BIOS is a 28 pin SOIC SRAM M48T18-100MH1. Datasheet can be found here....
http://pdf1.alldatasheet.com/datasheet-pdf/view/158323/STMICROELECTRONICS/M48T18-100MH1.htmlPiggybacked on this chip is one M4T28-BR12SH1 which is a socketed lithium battery / clock crystal combination to keep the SRAM data alive.
Datasheet...
http://www.st.com/web/en/resource/technical/document/datasheet/CD00149846.pdfIf I can,,,,, Big IF... I need to come up with a procedure to copy the only good BIOS and clone it over to the other chips while replacing the battery / crystal module.
So, my questions are.....
1. Does this sound feasible to just clone the BOIS and get a working motherboard?
2. Can I clone the chip with it soldered to the board? I see no JTAG plugs or any external programming ports.
3. I need to come up with a plan to keep the good BIOS alive when I replace the battery pack. What is the best route?
4. This #^$@ battery / crystal piggyback pack blocks the ability to use an SOIC pin clip to reach the pins. I'd need to come up with some sort of custom rig to touch the pins for reading / writing or desolder the chip with the battery in place.
5. Can I really do this......
I really have no clue what I'm doing, any help or advice would be GREATLY appreciated! I can supply detailed pictures and data on everything within my knowledge.
Thanks!
Adam