Thursday, December 20, 2007

Using Memtest86

A Story...

About Memtest, actually memtest86 and memtest86+ this program will fit on a floppy and also run off of a live CD. It is as the name suggest a program to test Memory on x86 based computers.

Some time ago ( circa 2007 ) we were having problems with an old Pentium 90 machine at work it ran DOS but we had to have it up and running ( the old software would not run on a newer faster machine ). The software was running funny it would work, some times for days then really mess up. My first thought was that something was wrong with the memory. Because it was such an old computer, it could not boot from the CD ROM but it could from floppy. Memtest86 was a quick download, of a floppy image.

I stuck in the floppy and booted memtest86 it loaded the start screen and then crashed. One of my coworkers said "Ya that floppy is defiantly bad." He pushed me out of the way and immediately put in a new floppy disk drive, then put in the original DOS boot disk back in. "Ya see it's the floppy disk"; Of course it booted back up, it had bootted that boot disk with the old floppy drive in also. "No I said it's the CPU" "No if it was the CPU it would not boot" he said.

I waked away until he left work. By then the computer had the same (old) error on the screen. I put memtest86 back in just to make sure it was not a problem with loading from a drive and it did the same thing the memtest86 loaded its screen up and then crashed. I put the old floppy back in the machine (I'll save the new one for a new machine) replaced the CPU and ran memtest86 for an hour or two until I was done with work. No errors then I put the put the DOS boot disk back in and let it run it has run for months with out any problems.

  • Memtest86 and Memtest86+ work best if you let them run for a long time; sometimes memory errors do not show up until the memory is nice and warm.
  • Know you memory test program regardless of what one you use I recognized the screen loading and crashing as ether one a CPU error or two a memory error in the first memory address.
  • If you have a coworker pushes you out of the way like this I wish you well. Don't take it personal, I walked away (in this example) knowing that this co-worker was going to be getting off work soon. Let your boss know you fixed it, and what the other person did.
  • To this day my co-worker insists that memtest and tool like it are useless. I and some of my other co-workers know better. Again know your tools so you can demonstrate to your boss.


No comments: