[comp.sys.ibm.pc.misc] Memory glitch?

norman@husc4.HARVARD.EDU (John Norman) (09/16/90)

memory glitch 
 
I have been having what seems to be a memory glitch on a DOS 2.11

system.  I can't tell if it is hardware or software, and I would

be curious to know if the problems I've been having seem to 
resemble typical problems indicating hardware (power, faulty 
board) or software (writing illigitimately into DOS, etc.). 
 
It is highly unlikely that this system has been exposed to 
viruses.  DOS is in ROM, and all software has been reloaded from

factory originals. 
 
The problems are: 
 
1.   After booting, when certain programs are invocated, they 
     will load from disk (RAM or physical), and before beginning

     execution will return to the command prompt with no output 
     and no error messages.  The disk from which they were loaded

     will have 2K fewer bytes free.  It's as though a file has 
     been deleted, but the free blocks haven't been returned to 
     the disk's directory. 
 
2.   Subsequent invocations will then work.  The 2K will still be

     magically gone. 
 
3.   Ocassionally some of the screen memory is written over.  A 
     rectangular block is copied to a different location.  When 
     this happens, character output slows down (even in, say, the

     DIR command, as well as applications).  Either there's some

     weird thing happening in the single-character output 
     routine, or the OS is slowed down generally by some weird 
     loop. 
 
This is incredibly annoying, and I simply can't tell exactly 
what's going on.  The machine is a Toshiba T1000 with an 
"extended memory" upgrade.  My guess is that it's some kind of 
power problem with the rechargeable battery, or some of the ROM 
is flakey, or some of the RAM is screwed up.  Any ideas? 
 
Are there any memory tools on SIMTEL20 that might help me isolate

bad memory? 
 
norman@husc4.harvard.edu 


John Norman
Department of English and American Literature and Language
Warren House Box E-13
Harvard University
Cambridge, MA  02138
617/495-2533 (Official business ONLY)

UUCP:      harvard!husc4!norman
Domain:    norman@husc4.harvard.edu
BITNET:    NORMAN@HULAW1

mlord@bwdls58.bnr.ca (Mark Lord) (09/19/90)

In article <4190@husc6.harvard.edu> norman@husc4.UUCP () writes:
>memory glitch 
> 
>I have been having what seems to be a memory glitch on a DOS 2.11
...
>It is highly unlikely that this system has been exposed to 
>viruses.  DOS is in ROM, and all software has been reloaded from
>factory originals. 

This does not guarantee getting rid of viruses, and the rest of the
description sounds an awful lot like a virus.  No guarantees though.

To get rid of viruses, remove all diskettes, turn on the cpu, wait
for DOS (from rom) to come up, insert your original DOS utilities
disk containing the FORMAT command, and reformat all of your working
disks.  

Of course this only works if your DOS utilities diskette has been 
write-protected (tab) since before the first time you EVER used it,
as otherwise it too probably has caught the virus by now.  The same
goes for all other "factory originals".  

First law of Safe-Exchanges:  write protect the "factory original"
BEFORE EVER inserting it into your system.

Second law of Safe-Ex:  run a virus scan program on all factory 
originals before EVER running any software off of them, as even 
these may arrive with viruses (unknown to the factory, of course).
-- 
 ___Mark S. Lord__________________________________________
| ..uunet!bnrgate!mlord%bmerh724 | Climb Free Or Die (NH) |
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