Hello,
Anybody know of a good way to test RAM memorory locations. My concern is I could be writing variables in c to memory locations that are corrupt. I have SD PC100 ram on my system and I just want to prolong it working as long as I can.

The best thing I have ever found to test memory AND CPU at the same time has been to run HPL (High-Performance Linpak) jobs on a machine for about 48 hours straight. It tests all of the memory if you use the right size problem, and also excercises the daylights out of your CPU and northbridge.

Another choice you have is memtest86 or memtest86+, which is quite a bit more portable as it will fit on a bootable floppy. The only problem I have found with memtest86 is that it does not really fully punish memory the way HPL seems to. On machines that I have run memtest86 cleanly on for 48 hours, I have gotten residual errors and MCE errors on a regular basis with HPL.

As a warning, getting HPL to work can be a chore in itself, and is much harder to get up and working than memtest86 is.