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From: plocher@sally.Sun.COM (John Plocher)
Newsgroups: comp.unix.i386
Subject: Re: VP/ix and Merge instruction sets (Was: Re: Can protected mode...)
Message-ID: <128424@sun.Eng.Sun.COM>
Date: 27 Nov 89 20:50:10 GMT
References: <256D58FD.14619@maccs.dcss.mcmaster.ca> <128383@sun.Eng.Sun.COM> <16784@nuchat.UUCP>
Sender: news@sun.Eng.Sun.COM
Reply-To: plocher@sun.UUCP (John Plocher)
Organization: Sun Microsystems, Mountain View
Lines: 19

+-- In <16784@nuchat.UUCP> Steve Nuchia writes
| In article <128383@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