Will Xenix 286 software run on Microport 386?

[john.urban]

In article <1991May31.085731.1660 at weyrich.UUCP> orville at weyrich.UUCP (Orville R. Weyrich) writes:
>I have been offered an obsolete RM/Cobol (ANSI-74) which has a dev sys and 
>runtime for a 286 Xenix. I have heard that Interactive and SCO are binary 
>comptable. 
>
>What is the chance of a compiler/dev sys/runtime intended for 286 Xenix
>running on Microport System V/386r3, and producing programs that will run
>on the Microport System V/386r3? I don't care if it is slow and can't handle
>huge programs.

Under UNIX System V/386 Release 3.2 (or higher) the odds quite high that
that the 286 XENIX Application will run.  The merged Microsoft XENIX and
System V occured in UNIX System V/386 Release 3.2, so if your version is
prior to 3.2 (ie 3.1) it won't work.

Under UNIX System V/386 Release 4.0, the odds lower.  Why is this?  Well
many XENIX Application don't user opendir(), readdir() ... but hard code
reads of 16 when accessing the directory.  The XENIX Filesystem and the
Standard UNIX filesystem (s5) are very similar.  So the reads of 16 work
on s5 or xenix filesystems.  However, if you run the XENIX application on
a UFS filesystems, things will start breaking if they start looking at the
directory and assume the 16 character layout.

Sincerely,

John Ben Urban