I know: I earned my beans as a Dos programmer for some time :-)
And that is the very reason I liked Linux from the moment I first tried it: it did the things I always wanted Dos to do, but it didn't, like multitasking.
Dos 5 or 6 (not sure) included a task manager shell that could run several programs, and switch between them - instead of using windows 3.x - but it was even more unstable than windows. There were commercial programs, like sidekick, that could give the appearance of multi-tasking. However, DOS 5 and 6 were incapable of multi-tasking per se. It used a facility called Terminate and Stay Resident, where a task would tell DOS it was terminating, but not to free up its memory. That task would use some facility, such as an interrupt to gain control. However this was very dangerous, and the
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On Mon, 17 Nov 2003 20:59:40 +0100 (CET)
"Carlos E. R."