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The 8086 was the first microprocessor UNIX was ported to. Maybe unsurprising as the first 16 bit processor that could address more than 64 KB of RAM. 8086 seg

by retrac 5y ago

The 8086 was the first microprocessor UNIX was ported to. Maybe unsurprising as the first 16 bit processor that could address more than 64 KB of RAM. 8086 segmentation was and is much-lamented, but it did enable a poor man's form of virtual memory. If the user process never touched the segment registers, the OS could move allocated code, stack and data blocks in RAM around transparently to the process. It also allows every process to assume it starts at address 0.

rbanffy 5y ago
> it did enable a poor man's form of virtual memory. Indeed. As long as you didn't need more than 64K, you'd be completely happy. That, and malloc would fail if you asked for too much memory.
jacquesm 5y ago
Before OS/9?
- deleted 5y ago
  [deleted]
- retrac 5y ago
  I think so. The 8086 port was done at AT&T in 1978. Xenix was based on that work.
  - jacquesm 5y ago
    Close call then with OS/9 released in '79.