VP/ix and Merge instruction sets (Was: Re: Can protected mode...)

John Plocher plocher at sally.Sun.COM
Tue Nov 28 07:50:10 AEST 1989

+-- In <16784 at nuchat.UUCP> Steve Nuchia writes
| In article <128383 at sun.Eng.Sun.COM> John Plocher writes:
| >No, DosMerge and VP/ix both run DOS in a virtual 8086 environment.
| What about the 32 bit instructions?  If one is content to live with

If the instructions exist on the 8086 you can use them in the
virtual 8086 mode.  This is a "hardware" mode of the 80386, not
a software emulation under Unix.  If the program won't run on
an IBM XT, it won't run under 80386 VP/ix or 80386 Merge.

The Microport 80286 Merge runs the DOS programs in Real Mode
on the '286, so a program "could" switch into protected mode
and do stuff, but it *WOULD* corrupt the memory and data
structures used by Unix; the program would crash when the next
interrupt came in :-)

    -John Plocher

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