padgett%tccslr.dnet@uvs1.orl.mmc.com (Padgett Peterson) (08/31/90)
Last night I started receiving alarming messages form my home PC. Messages like "CANNOT LOAD COMMAND.COM" & "GENERAL FAILURE ERROR" (on the hard drive) plus boot failures and CMOS trashing. The odd thing was that if I booted from floppy everything was fine & Norton reported everything allright. Applying Occam's Razor, I removed the LOADHI.SYS from the 10k trackball driver just added the day before and let it load low. Having noted some erratic behaviour from things loaded into high memory before (applications failing strangely, odd display action), this was my first thought. Apparently my high memory manager (QEMM 5.0) has some problems deciding what high memory is actually unused. In this case, I suspect that the T'ball driver's buffer was overlaying part of the hard disk controller (In shadow ram & evidently mutable). But then, if my high memory were not already overloaded with video, Bernoulli, anti-virus, print, disk-cache, and keyboard utilities already, I would not have a problem. Now if I can just figure out DesqView... Meanwhile, I have not had time to make a detailed analysis of just what happened but have noticed a few threads mentioning the same sort of behaviour & suspect that since my machine has an AMI BIOS with C&T chipset, it is probably the rule rather than the exception. Two factors stand out: the potential for accidental misuse of high memory could have drastic consequences (consider such an happening during DEFRAG operations) & for an "at risk" machine, the performance gain from shadowing must be weighed against the potential for malicious damage. Of course if the vendors would just get their act together & produce machine speed BIOS (wiring, NOT the fact that it is in ROM) like they have in upscale video cards the answer would be simple - except we probably would not pay for it. Oh, Well. Padgett