J-Mark (JetWay?) J-630BF missing BIOS chip

Hot-swapping and Boot-Block flash & Boot block flash and floppy support
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trilioni
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Posts: 3
Joined: Sun Nov 26, 2006 8:48 pm

I have one motherboard that has an BIOS chip completely missing. Can someone tell me what kind of a chip should i use, or what kind of chip the mobo came with? Found the image of the bios that has the size of 256kb so i guess it is 2MB FLASH chip. Am i right? Is there any pin difference between various chips? Can something like this be used on this motherboard? >>2MB Chip from Jameco

Any info would be of great help :)
cp
BIOS Guru
Posts: 1914
Joined: Mon Oct 21, 2002 9:07 pm
Location: Germany

take a look at this:

http://www.futurlec.com/Datasheet/Memory/AT29C020.pdf

and measure the voltages. there are mainboards that use 12V flash eeproms, too. btw. size calculated correctly :)
trilioni
New visitors - please read the rules.
Posts: 3
Joined: Sun Nov 26, 2006 8:48 pm

Does the motherboard get any power on BIOS chip pins without any CPU or add-on card installed? Or do i have to measure V with cpu in the socket and memory in the slots?
One more thing, can i use EPROM instead? (27c020) I assume the only differnece in pinounts is pin 1 which is Vpp - Program Supply in EPROM and not connected on flash.
cp
BIOS Guru
Posts: 1914
Joined: Mon Oct 21, 2002 9:07 pm
Location: Germany

voltages are on the chip as soon as you power up the board. no need to plug in anything else.
you can use an eprom, too. you can even build an adaptor if the pinout is different. just make sure the address, data and power pins are connected (and the device is selected (_CE) and outputs are enabled (_OE)).
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