BLCARR01@ULKYVX.BITNET (09/21/89)
I need to obtain a replacement for one of the PAL chips on my PC6300 motherboard. The chip is located at position 6E on the motherboard which is immediately adjacent to the two ROM BIOS chips. It has a label of PL54 (or maybe PL74--I can't tell for sure which one it is). According to my copy of SAM'S COMPUTERFACTS for the AT&T PC6300 the chip is a fairly standard one with a part number of PAL12L10CNS and should be easily programmed with a PROM programmer provided that I had another chip from which to make a new copy. I have called AT&T's Technical Support number at 1-800-922-0354 many times trying to find someone who can give me the COMCODE number for this particular chip, but all I can get from them is that I have to talk to an engineer at the rate of $120/hour usable in quarter-hour increments. I did let them sell me a ROM BIOS 1.43 upgrade (I already have 1.43) because they told me that there was a PAL chip included with the two ROM BIOS chips. They wouldn't tell me which PAL chip it was but I went ahead and ordered it anyway hoping for the best, alas it was a PL90 chip located at position 2P. I have called AT&T's ComCode Hotline number at 1-800-654-5832, but they weren't able to give me a comcode number for the chip that I need. They did give me, however, the phone number of a nearby AT&T Service Center to call which I did. The Service Center told me to call 1-800-922-0354 and not to bother them. Why do I need a replacement for this chip? I am trying to install a high density floppy disk with a floppy disk controller card that is advertised to work with existing floppy disk controllers but apparently doesn't. It is possible to disable the motherboard floppy disk controller chip by removing one of the pins on the chip at location 6E. Pin 17 carries the control signal for the FDC765 floppy disk controller on the motherboard. I had pulled this chip from its socket and inserted it into a socket that I made with pin 17 removed and then placed the assembly with the untampered PAL chip back into the original socket, except that I inadvertently put it in backwards. When I turned on the power the chip got fried--I'm afraid that it is no longer usable and that some other PROM chips may have been damaged, too. If you have a suggestion that could help me find a replacement for this chip I would be most happy if you would send it to me. My return mail address is given below. Thank you very much. Brent Carruth Dept of Eng Math and Comp Sci Univ of Louisville Louisville, KY BLCARR01@ULKYVX.BITNET