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The 386 has an MMU, making it feasible to do preemptive multitasking and virtual memory. The 286 and 8086 had multitasking based on allowing small programs to

The 386 has an MMU, making it feasible to do preemptive multitasking and virtual memory. The 286 and 8086 had multitasking based on allowing small programs to run concurrently, but nothing that used a lot of memory. The competing 68000 also lacked an MMU. The later 68010, I think, had the MMU.

code_duck 13y ago
The lack of preemptive multitasking didn't mean that people didn't want to run a Unix-like OS at home, if that's what you mean. MSDOS was horrible, and regardless of the capabilities of your machine one would probably rather use something else. I had Amigas with 68000s, and one with a 68030. AmigaOS didn't have any special capabilities on a 68030 that it didn't have running on a 68000. AmigaOS was a Unix-like IS with full preemptive multitasking that could operate in 256k of address space, on a 68000.
- wildgift 13y ago
  Oh yeah, DOS sucked. I remember Xenix and MKS and some other unixy toolkit. Oh yeah also Coherent. I ran a shell called Gulam on an Atari, and it was nice. Fake pipes were better than no pipes :) Did all the processes run in the same address space on the Amiga??
zurn 13y ago
You could do preemptive multitasking with memory protection on a 286. IBM & MS did it in OS/2. Actually looks like Xenix used that too. http://www.tenox.net/docs/microsoft_xenix_30_286_press_release.pdf http://www.tenox.net/docs/microsoft_xenix_30_286_press_relea...
- wildgift 13y ago
  Really? I though OS/2 was on the 386. I thought that the 286 had some limit on the size of a process, but you could execute multiple processes. I don't know why, but I think it was 64k per process. Also, the other thing I recall was thinking that it was a nice idea. I was only familiar with 68k so I'm probably wrong here.
  - zurn 13y ago
    Really. The 286 is a 16-bit CPU so there would have been various memory limits. http://www.os2museum.com/wp/?page_id=313 http://www.os2museum.com/wp/?page_id=313 has some details on what it can do, but not much mention of limits...

code_duck 13y ago

The lack of preemptive multitasking didn't mean that people didn't want to run a Unix-like OS at home, if that's what you mean. MSDOS was horrible, and regardless of the capabilities of your machine one would probably rather use something else. I had Amigas with 68000s, and one with a 68030. AmigaOS didn't have any special capabilities on a 68030 that it didn't have running on a 68000. AmigaOS was a Unix-like IS with full preemptive multitasking that could operate in 256k of address space, on a 68000.

wildgift 13y ago
Oh yeah, DOS sucked. I remember Xenix and MKS and some other unixy toolkit. Oh yeah also Coherent. I ran a shell called Gulam on an Atari, and it was nice. Fake pipes were better than no pipes :) Did all the processes run in the same address space on the Amiga??

zurn 13y ago

You could do preemptive multitasking with memory protection on a 286. IBM & MS did it in OS/2. Actually looks like Xenix used that too. http://www.tenox.net/docs/microsoft_xenix_30_286_press_release.pdf http://www.tenox.net/docs/microsoft_xenix_30_286_press_relea...

wildgift 13y ago
Really? I though OS/2 was on the 386. I thought that the 286 had some limit on the size of a process, but you could execute multiple processes. I don't know why, but I think it was 64k per process. Also, the other thing I recall was thinking that it was a nice idea. I was only familiar with 68k so I'm probably wrong here.
- zurn 13y ago
  Really. The 286 is a 16-bit CPU so there would have been various memory limits. http://www.os2museum.com/wp/?page_id=313 http://www.os2museum.com/wp/?page_id=313 has some details on what it can do, but not much mention of limits...