Dos and unix on same Disk

[Wally Kramer]

justicec at handel.cs.colostate.edu (Christopher Justice) writes:
>I'm having a problem installing both AT+T System V R3.2.2 and Dos 4.0 on
>the same disk drive.  I partioned the drive (330 meg) into an 80 meg Dos 
>partition and the rest for unix.  They installed succesfully, but Dos gives
>me a "General failure reading drive C:" when I try to run programs.  This
>happens irregularly.  Unix has given me a couple of "unrequested harddrive
>interrupt errors". 
...
I've done this with SCO Unix (*not* Xenix).  There were two ways I've done
it.  Method 1 is to keep the first partition DOS, as DOS (3.30 at least)
seems to care.  Make the second partition Unix and make it bootable (the
"active" partition).

Unix boots by default.  To boot DOS, just stick in a DOS floppy and boot
from that.  My autoexec.bat on the disk just ran c:autoexec and the
config.sys on the floppy was the same as the one on the hard drive.

Method 2, used with a later release of SCO Unix, used the same partitioning
strategy, but made use of a feature of the unix boot loader:  if you
typed "dos" instead of just return (or let it timeout), it would boot the
dos partition.
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Wally Kramer	contracted from Step Technology, Portland, Oregon 503 244 1239
wallyk at orca.WV.TEK.COM        +1 503 685 2658