Hi Alex,

> On Sun, 08 Mar 2009 16:20:40 +0100, I waved a wand and this message
> magically appears in front of Eric Auer:
>> Indeed a very annoying bug in FreeCOM 0.84 but nobody has yet found
>> a way to predict WHEN it happens. If you can find a way to make it
>> happen at a more specific time than "after a while", we could use a
>> debugger to find out what exactly happens when things break. Note
>> that only running com/exe/... (external commands) breaks, you can
>> typically still run internal commands like DIR. Is this the same bug
>> that you are experiencing?
> Smells like a stack overflow somewhere, methinks, 

Another option might be "overwriteable part of FreeCOM overwritten
but FreeCOM failed to notice"...? Background: It moves some data to
the end of some memory block and when you run a DOS app which does
not overwrite that block then FreeCOM can avoid having to restore
the data from XMS... There might be some code which decides about
whether restore-from-XMS is needed and which is too optimistic. But
maybe I am totally wrong about that whole swap/overwrite topic...

If the problem can be avoided by not loading EMM386, the cause might
be that EMM386 allows some area to be used by DOS (and freecom) as
UMB while that area has contents changed by BIOS or because of some
hardware activity (sound, network, usb, disk access etc etc)...?


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