archeocomp
Experienced Member
Hello. I have bought two PC/XTs off eBay Germany. One is PC 10 III with MFM card and HDD, the other one is PC 20 III with RLL HDD. I do not have any TTL monitor. Week ago as I only had the first one, I did power it up, just to let it heat up. Before everything went fine, I could hear the computer beep after RAM test, though I did not see anything. But this time after a while I heard an explosion and the power supply fan did exhaust a lot of smoke. So I switched it off and disassembled. A capacitor at the input in power supply exploded. I replaced it. Power supply seemed to work, I measured all the voltages and it seemed OK. So I started the PC agan. And it did not start. The LED in the front just blinks. So it seems, the motherboard is damaged. I removed the BIOS chip and wanted to read it contents. Sticker says it is BIOS4.36. All FF. I tried to program one byte. No succes. So the EPROM is dead. But I tested the MFM card in yet another PC/XT. It works !! So not everything has been burned. Today I received the other PC 20 III I mentioned in the beginning.
http://www.ebay.de/itm/110936163204?ssPageName=STRK:MEWNX:IT&_trksid=p3984.m1497.l2649
I cleaned it, it was very badly dusted, rosty. I wanted to read the BIOS chip. Sticker says it is BIOS 4.41. And it seems almost cleared. Here are the first lines:
:2000000055FFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFAA
:20002000FFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFE0
:2000400064FFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFF5B
:20006000FFFFFFFFFFFFFFFFF7FFFFFFFFFFFFFFFF07FFFFFFFFFFFFC7FFFFFFFFFFFFFFD8
I think the EPROM may not be dead, it only lost its contents. Now my question.
1. Could somebody please upload some BIOS for these PCs ?
2. I know nothing about different PC/XT BIOSes, are they interchangable ?
3. I see there is another CHAR ROM on the motherboard. Can someone upload it contents as well.
In a week or so I should receive this TRIDENT 9000 card, I want to test the PC with LCD VGA then. It hopefully is an 8 bit friendly card.
http://pocitace.aukro.cz/vga-karta-trident-i2551448516.html
Any thoughts, comments, help are welcome.
Regards,
Roman
http://www.ebay.de/itm/110936163204?ssPageName=STRK:MEWNX:IT&_trksid=p3984.m1497.l2649
I cleaned it, it was very badly dusted, rosty. I wanted to read the BIOS chip. Sticker says it is BIOS 4.41. And it seems almost cleared. Here are the first lines:
:2000000055FFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFAA
:20002000FFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFE0
:2000400064FFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFF5B
:20006000FFFFFFFFFFFFFFFFF7FFFFFFFFFFFFFFFF07FFFFFFFFFFFFC7FFFFFFFFFFFFFFD8
I think the EPROM may not be dead, it only lost its contents. Now my question.
1. Could somebody please upload some BIOS for these PCs ?
2. I know nothing about different PC/XT BIOSes, are they interchangable ?
3. I see there is another CHAR ROM on the motherboard. Can someone upload it contents as well.
In a week or so I should receive this TRIDENT 9000 card, I want to test the PC with LCD VGA then. It hopefully is an 8 bit friendly card.
http://pocitace.aukro.cz/vga-karta-trident-i2551448516.html
Any thoughts, comments, help are welcome.
Regards,
Roman