OS/2

From: Douglas Quebbeman <dhquebbeman_at_theestopinalgroup.com>
Date: Tue May 30 08:04:12 2000

> Eh? You're both wrong. OS/2 used the protected-mode multi-segment
> support of the x86, but recall that OS/2 was originally released on the
> 286 -- it didn't have any paging support. It's easy to distinguish a
> fault during a CS load from a GPF, and no page fault is involved.

There is another factor complicating this history lesson.

The most extant machine that was OS/2 capable at the time of its
launch was the IBM PC/AT. Most of the PC/AT models shipped with
mask C of the 80286 processor. There was a flaw in the C mask chip
that caused the CX register to be trashed on a GPF.

That meant for OS/2 to take advantage of this hardware feature would
have required a processor upgrade (they were socketed, PGA) for all
these machines.

Still, how hard would it have been to include a chip in the package?

-dq
Received on Tue May 30 2000 - 08:04:12 BST