mason@unify.uucp (Mark Mason) (04/06/90)
Hello,
I just got ahold of an old IBM PC (real IBM), and keyboard input does
not seem to work. I have tried all of the real simple stuff (keyboard
and cable work fine on another machine, connector->mother board
connections are good according to my ohmmeter, tried a lot of
wiggling, etc).
When power is turned on, the following occurres:
"301" is printed in the upper left corner of the screen.
memory is checked (passes, god is it slow!)
floppy drive is accessed for a moment (reset?)
beeps twice
"ERROR. (RESUME = F1 key)" is displayed
Hitting F1 (or any other key) does nothing. (even caps lock does not
cause the light to turn on). The keyboard does seem to get power (the
keyboard lights all flashed sometime earlier in the boot process).
Any ideas?
I have a lot of replacement chips on hand, what I don't have at the
moment is an oscilloscope or a logic probe (thinking about getting the
latter), and I don't want to go replacing chips blindly. I do suspect
the 'ls322 shift register and the interval timer (a hunch), but I
wanted to wait for some feedback before doing anything rash (none of
these guys are in sockets...).
I would appreciate any advice on how to fix this beast.
Thanks alot,
Mark Mason
tektronix!pyramid!unify!mason
--
{{ucdavis,csun,lll-crg}!csusac,pyramid,sequent}!unify!mason
-or- mason@reed.bitnet
The above opinions/falsehoods/misconceptions are my own....phil@pepsi.amd.com (Phil Ngai) (04/06/90)
In article <6746fbq@unify.uucp> mason@unify.UUCP () writes: |When power is turned on, the following occurres: |"301" is printed in the upper left corner of the screen. That means a keyboard error. |memory is checked (passes, god is it slow!) I recommend you replace the motherboard with a faster one, preferably a 386. While you're at it, you may as well get a bigger power supply and of course you'll need a new case to match the new motherboard's card spacing. You'll probably want a 16-bit disk controller and a VGA display/card too. I also highly recommend a 1.2 megabyte floppy disk and a large hard disk. :-) -- Phil Ngai, phil@amd.com {uunet,decwrl,ucbvax}!amdcad!phil Spring is here!
besler@cetus.mi.org (Brent H. Besler) (04/06/90)
I wouldplug in a known good keyboard to make sure the proble is located in the keyboard itself. You might consider putting a cheap clone keyboard on it for about $40-$50. A good one like the Northgate or Keytronics runs closer to $100.
segal@motcid.UUCP (Gary Segal) (04/07/90)
The following contains confusing information; read on: mason@unify.uucp (Mark Mason) writes: >I just got ahold of an old IBM PC (real IBM), and keyboard input does >not seem to work. ... Ok, I'm assuming a 5 slot PC with IBM roms dated 10/27/82. >When power is turned on, the following occurres: >"301" is printed in the upper left corner of the screen. "301" indicates a general keyboard failure, or keyboard not present. "301 xx" indicates that the key with scan code xx is stuck. >memory is checked (passes, god is it slow!) Does the machine display the memory as it checks it? If so, you have XT roms, not PC roms. PC's display nothing but a flashing cursor while they check memory. >"ERROR. (RESUME = F1 key)" is displayed Hmm... IBM PC roms never display "ERROR. (RESUME = F1 key)", however IBM XT roms do. >Hitting F1 (or any other key) does nothing. (even caps lock does not >cause the light to turn on). The keyboard does seem to get power (the >keyboard lights all flashed sometime earlier in the boot process). Hmm again... IBM PC and XT keyboards never had lights on them. AT keyboards did, and so do some clone keyboards. It sounds like you have a keyboard that doesn't match your system. An IBM PC has 5 slots, a keyboard port and a cassette port (for when you run out of hard disk space :-). An XT has 8 slots, and no cassette ports. Both use the same keyboard, which does not have any lights on it. AT's use a different keyboard, which have lights, but they don't work on XT's or PC's. It sounds like you have an XT, not a PC, and a AT keyboard, which doesn't work with an XT. If it's not an IBM keyboard, hunt around for a dip switch, lots of the clone keyboards are switchable between PC/XT and AT mode. -- "If you've done six impossible things this morning, | Gary Segal, Motorola CID why not finish it up with breakfast at MillieWays, | 1501 W. Shure Drive the Restaurant at the End of the Universe!" | Arlington Heights, IL 60004 | ...!uunet!motcid!segal