don@trsvax.UUCP (03/17/91)
> every so often, after completing an application, > like Quicken, instead of getting back my DOS prompt, > I'll get the Invalid COMMAND.COM message, need to re-boot. I've seen this before. We were working on a non-dedicated Novell server. When COMMAND.COM is loaded, part is loaded low and part high in memory. The high memory is not allocated, so programs are allowed to use that memory. When you execute a program from COMMAND.COM, the new program is loaded low in memory after the low part of COMMAND.COM. When the program terminates, control is returned to the low part of COMMAND.COM, which then performs a test to see whether the high part of COMMAND.COM is valid or not. I'm not sure what the test is, but we found a situation which was overwriting the high part of COMMAND.COM but the low part did not correctly determine this fact. As a result, COMMAND.COM was not being reloaded when it needed to be. To solve the problem, we adjusted the new program so that it would not load over the very top of memory. Note that this solution requires modifying the new program. I have not found a general solution which guarantees this scenario will never occur. Anyone else have any solution which has been successfully implemented? --------------------------------------------------------------------------- Hardware: The parts of a computer system that can be kicked. Don Subt The opinions expressed above are Tandy Corp. strictly mine, not my employer's. 817-390-2923 don%trsvax@rwsys.lonestar.org