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| Author |
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keesan
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Computer hardware questions
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Mar 29 20:06 UTC 2002 |
Post any computer-hardware related questions including discussions of obsolete
computers.
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| 205 responses total. |
keesan
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response 1 of 205:
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Mar 29 20:09 UTC 2002 |
What is likely to be the cause of the following problems with a 486DX2 66:
Will not reboot with Ctl-Alt-Del, but reboots randomly while running things
like edit. After running defrag crashes and screen blinks, won't reboot.
Occasional GPF error blamed on emm386.exe.
Jim is thinking of reseating the BIOS and RAM and cpu. Other ideas?
None of this is easily repeatable except for failure to reboot when desired.
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keesan
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response 2 of 205:
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Mar 29 22:06 UTC 2002 |
Bill L says this is a software problem having to do with emm386 and buffers
and memory. I will try removing emm386 to see if it will boot then.
It also sometimes does not accept any keyboard input.
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keesan
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response 3 of 205:
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Mar 29 22:29 UTC 2002 |
Remarking out the emm386 line in config.sys allows me to reboot.
Has anyone else used DRDOS with emm386.exe? frame=none dpmi=off
dos=high,umb No himem.sys. Kermit sends much smaller packets
with only 1M RAM accessible.
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keesan
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response 4 of 205:
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Mar 29 22:41 UTC 2002 |
Might the problem be some conflict between DRDOS and the cpu, which identifies
as SGS-Thompson ST486D? (Is this a Cyrix cpu?) Can we change the cpu to an
Intel or are they board dependent?
Hoping to give this computer to someone out of town on Sunday, with more than
1M usable. (A viewer will only show 1/4 of the image with 1M).
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jazz
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response 5 of 205:
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Mar 29 23:42 UTC 2002 |
It's probably a busted flux capacitor.
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oval
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response 6 of 205:
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Mar 29 23:50 UTC 2002 |
aw DAMN!
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keesan
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response 7 of 205:
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Mar 30 00:42 UTC 2002 |
Jim wants to try emm386.exe from MSDOS on this DRDOS computer. I will report
the results. I would like to simply try MSDOS on it.
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gull
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response 8 of 205:
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Mar 30 01:09 UTC 2002 |
There's a switch you can give EMM386 that fixes the reboot problem. I don't
remember what it is, but it's in the help.
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keesan
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response 9 of 205:
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Mar 30 01:16 UTC 2002 |
We are using dpmi=off and frame=none, are those relevant to the problem?
Thanks for the clue (and for ghostview).
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gull
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response 10 of 205:
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Mar 30 01:20 UTC 2002 |
AltBoot
Specifies that EMM386 use an alternate handler to restart your
computer when you press Ctrl+Alt+Del. Use this switch only if your computer
stops responding or exhibits other unusual behavior when EMM386 is loaded
and you press Ctrl+Alt+Del.
That's for the DOS 7 version, I don't know when that switch was added.
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keesan
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response 11 of 205:
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Mar 30 04:33 UTC 2002 |
I tried this as /altboot at the end of the line. Got a list of possible
things you can put on the emm386 line as a result. Altboot is not one of
them. DRDOS 7.03. We are trying to figure out what range to exclude and may
do exclude= the areas where the video ram is.
Perhaps it is just altboot without the /? I am lost.
We just excluded c000-c7ff,e000-f3ff and it won't boot again.
Next thing to try is getting rid of DRDOS 7.03 and using MSDOS 6.22, which
I wanted to do in the first place.
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bdh3
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response 12 of 205:
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Mar 30 04:56 UTC 2002 |
(man. 10 years ago I used to have to know that kinda shit)
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keesan
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response 13 of 205:
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Mar 30 05:23 UTC 2002 |
We did scandisk and the file structure is okay. Replaced the DRDOS system
files and emm386.exe. Ran DRDOS from a boot disk with files from a known
working computer. None of this helps. The computer works with DRDOS unless
we use emm386.exe with it. The emm386.exe is from DRDOS 7.03.
So we made an MSDOS boot disk with emm386 and himem.sys in config.sys and on
the disk and booted with that. Then tried to look at the c: drive and all
the file names are in Greek characters. Repeated this a few times.
This means the computer is unusable with MSDOS, I think.
Is this an extreme case of cpu incompatibility? It is a Thompson cpu, not
an Intel (cyric?) ST486D. Bad cpu, bad BIOS?
Time to move the hard drive (which is 80M and has only one B on it when we
run scandisk) to a new box? We can set it up with 3M RAM in an ATT.
I was just offered a used Pentium 200MHz with CD-ROM drive and sound card.
Maybe I can give my old ATT to Jim's sister instead of the oddball.
Redoing the MBR also did not help.
Why would MSDOS do worse than DRDOS? If we boot from a DRDOS floppy disk we
can read the file names in c:, but not if we boot with MSDOS.
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keesan
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response 14 of 205:
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Mar 30 05:31 UTC 2002 |
Jim ran McAfee virus checker. Found no viruses but said
Read access to file C;\ XXXXXXX denied. - the XXXX being a bunch of
upper ascii characters. Six files denied access. This was run under MSDOS.
If we put the hard drive in another computer and the problem follows, it is
software, otherwise probably hardware. More later this morning.
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keesan
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response 15 of 205:
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Mar 30 05:39 UTC 2002 |
McAfee run under DRDOS could access all the files and found no viruses.
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keesan
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response 16 of 205:
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Mar 30 13:42 UTC 2002 |
We are about to try a replacement controller card. The modem (which is
plugged into this one) also has problems - won't hang up when expected to with
one program (Termin). Back soon.
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keesan
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response 17 of 205:
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Mar 30 13:53 UTC 2002 |
With the new controller card it won't boot - it gets stuck on
512K memory in the video card and won't boot the rest of the way.
The controller card worked somewhere else. Jim wonders if the board is set
wrong for its Cyrix cpu and will try an Intel cpu.
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keesan
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response 18 of 205:
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Mar 30 16:40 UTC 2002 |
We forgot to turn the computer off. In the morning it would not boot from
the hard drive. We tried replacing cpu, video card, and controller card and
concluded it was a bad motherboard. We recycled the computer and saved the
battery, video card, controller card, jumpers (white and red ones) and the
hard drive. We moved the hard drive to our computer with 2 72-pin slots
(which we have 2M SIMMs for) and the new computer would not boot from the hard
drive. It would boot from a DR-DOS floppy and also reboot (one less problem
than before) but when we booted from MS-DOS floppy it had more problems -
instead of displaying 3.5G and Greek file names (on an 80M HD) it could not
access C: at all. We made this drive slave and an identical one master and
could boot from C: and when running MS-DOS from C: then the original HD (from
the other computer) displayed file names as Greek letters again.
We have a bad hard drive, obviously. Since DR-DOS can at least read that
drive though won't boot from it we are reformatting c:, scandisk, and will
attempt to transfer the files to it and scrap the hard drive.
The other computer was no great loss - 4x30 pin slots (4M max) and was missing
the covers for two large bays (we put in cardboard instead). Too many
computers.
Jim points out that the newer (post 1990) hard drives (IDE) have part of the
controller incorporated in them and that was apparently affecting the rest
of the computer even when we did not boot from the HD. We should have pulled
the cable off the HD before booting from floppy to test.
We are formatting c: /s /u /x.
Comments on hard drives and controllers welcome - what different types of hard
drives are there and when did they start having the controller included?
MFM IDE RLL ESDI SCSI (from Build Your Own 486 and Save a Bundle - back when
a 486DX cpu was $600 for 50MHz and $1000 for 66MHx DX2. We have thousands
of dollars worth of cpus! What does a cpu cost now?
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keesan
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response 19 of 205:
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Mar 30 16:44 UTC 2002 |
No problem in copying from the bad HD using DR-DOS, but MS-DOS was useless
in that respect. Jim has convinced me to switch to DR-DOS.
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keesan
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response 20 of 205:
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Mar 30 16:54 UTC 2002 |
The problem seems to have followed the software. New hard drive won't boot
now. ??????? We had done an unconditional format. MS-DOS can now read the
hard drive, it just won't boot from it. We will convert this back to an
MS-DOS computer. Stay tuned.
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keesan
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response 21 of 205:
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Mar 30 17:17 UTC 2002 |
The computer (the one we did not recycle) with the second hard drive (the
first would probably also have worked) is doing fine as an MS-DOS computer.
I had begged Jim to set it up that way in the first place. I am still using
two temporary computers because he wanted to set up the good ones with DR-DOS
and in the meantime I put together something that I could understand, about
three years ago. I have two pentiums not in use because of DR-DOS. Jim just
left without saying goodbye after I asked him to please not set up any more
computers for my use with DR-DOS on them. One full day wasted. The whole DOS
directory deleted off the hard drive and the files have to be put back on via
floppy disk.
Now I get to learn to replace RAM unsupervised.
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raven
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response 22 of 205:
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Mar 30 20:22 UTC 2002 |
Hmmm I love to recycle and everything but is it really worth putting 20
hours of effort into a 486 worth maybe 20 bucks, when a Pentium 133 class
machine can be had for 50 bucks. Even at minimum wage it seems like it
would make more sense to work 10 hours and buy the persons the Pentium.
Of course you should make sure the 486 is disposed of properly and doesn't
wind up in a land fill, but it seems like a 486 on the blink isn't worth
the hassle to try and fix.
re #18 CPUS are pretty cheap now you can get a Duron 1 ghz CPU that is
about 30 (?) times as fast as those 486s for about a hundred bucks.
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keesan
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response 23 of 205:
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Mar 30 20:35 UTC 2002 |
We don't need anything more powerful than a speeding bullet just to access
mnet from Warren and display photos from our camera. We are learning
something this way, at least.
I am suspecting that Jim may have formatted the hard drive with MS-DOS and
then put DR-DOS on it and they don't like each other. He thinks he used
DR-DOS format but is not sure.
I learned three ways to install a controller card wrong (dont' push it in far
enough, put the cable to the floppy drive on only half the way, and put the
cable to the serial ports on so that it does not cover the end pin or
alternatively so it does not cover one of the two rows of pins. Hard to see
what I am doing in there. I pull the plug first.
I have PCPlus and Kermit working on Com1 and am trying to convince Lynx to
also behave. It worked once but then could not find the nameservers. It was
working yesterday - same software, controller card and modem. I think I may
have messed up a setting (mru, whatever that is, should not be set equall to
mss).
We don't use a mouse so I put in only one com port this time. Attached to
Com2 plug, it does not get recognized as com2. I made it com1. Lynx was
working before as Com2....
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raven
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response 24 of 205:
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Mar 30 21:16 UTC 2002 |
I'm not saying don't tinker I love to tinker, just tinker with something
more usable, at this point you could probably dumpster dive a Pentium
166 level system pretty easily. Another place to look is the dumpster
outside U of M property disposition.
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