padgett%tccslr.dnet@uvs1.orl.mmc.com (07/18/90)
I have seen this on a number of machines (Compaq particularly) that reserve 1k of top memory for drivers/etc (Compaq claims it is for its mouse & can be recovered by moving a jumper on the mother board). There are a couple of viruses that use this same technique in software (Brain, Yale) but the reserved area is usually larger than 1k and it contains executable code. The conflict comes about because some memory checkers use Int 21 Fn 48 to determine free memory, others use Int 12, while some just look at 0:413 & 414 for the number of reported segments. These may report differently. The best tool I have seen for checking is Quarterdeck's MANIFEST though it can be confused sometimes. The freeware (?) program MAPMEM by Turbopower Software when used with the /V (verbose) option is also very good.