I have an old motherboard, FIC 486-GVT-2 which uses a 28-Pin EPROM (27C512) which is 64K
Now, the last BIOS (4 years newer than the current one) for this board is 128K, so obviously I can't use the old chip
But the socket is 32 pin, and with the old chip removed there is screened on the board "FROM - 128k * 8" so I expect I can use a 1mbit/128K part in there.
My question here is: is it electrically compatible? For example, if I were to use a 29C010? as it is, the current chip is plugged in so pin 1 of the chip plugs into pin 3 of the socket:
http://flickr.com/photos/agent_24/2491103673/
http://flickr.com/photos/agent_24/2491938548/
The pins are compatible bar pin 28 which becomes pin 30 and changes from Vcc to NC, and Vcc moves to Pin 32.
As for pins 1, 2 & 31 for support in the socket I have no idea.
I don't need to be able to program the new chip in the PC but it would need to boot up and work normally obviously.
Or would I only be able to use a EPROM like 27C010?
Does anyone have any thoughts on this?
28 Pin EPROM in 32Pin Socket - Can I install a 32pin EEPROM?
yes. pin30 is NC on the 29C and should be shorted to pin32 on the socket. take a multimeter and check it. for the other pins: _WE is Write Enable which _should_ make it possible to flash the 29C on this board, too. but to reduce risks i wouldn't test that. except you have a stash of 29Cs floating around somewhere ;)My question here is: is it electrically compatible?
A16 is the address line you need for the additional 64k on the 29C and pin1 is NC anyway.
my recommendation is: check if VCC is connected to pin32 on the socket. if it is not: just short it to pin30. flash the 29C with the latest bios and plug it in.
If you email me include [WIMSBIOS] in the subject.
