BIOS

[Charles Steinkuehler]

Rusty wrote:

> I may have spoken too soon in my earlier follow-up post about this BIOS
> chip. It appears to be a DIP chip, but it looks like it is in some kind
> of another mount. I don't know hardware details well enough to know if
> this is a different "package" or not. I don't have a chip puller, and I
> can't budge the chip by hand. I don't really want to trash it by trying
> harder at this point.
> 
> The info off the chip is this:
> There is a Phoenix BIOS sticker that has "D686 BIOS" and the number
> "054089790" on it. Under the sticker is: "Winbond" the number
> "W29C020C" and the number "1090I2047361Y2SA".
> 
> Does that tell anyone anything useful?

Yes...the 29C020 is a standard flash part made by many manufacturers, 
and the Winbond W29C020C is a DIP package according to the datasheet.

The part will either be soldered directly onto the board, or it will be 
in a socket (with the socket actually soldered onto the board).

It sounds like your part is socketed, so you should be able to simply 
remove it from the socket and cart it somewhere to access a programmer. 
It would be almost impossible to get the part out of the socket by hand, 
typically a small screwdriver is used to assist removal.  Insert the 
blade of a small, flat screwdriver between the chip and the socket, then 
turn the screwdriver (like you were screwing in a screw) to leverage the 
chip out of the socket a bit.  Then switch to the other end of the chip 
and leverage it out a bit.  Repeat as necessary, alternating ends so you 
won't bend any of the pins too bad, and soon the chip will be removed 
from the motherboard.

BTW:  Don't overly stress about pulling the chip.  If you bend some of 
the pins (likely when one end of the chip decides to 'pop' out) they can 
be bent back.  If you totally destroy the part, they're about $5-6 from 
DigiKey if someone doesn't have a spare laying around you could mooch.

-- 
Charles Steinkuehler
charles at steinkuehler.net