SunOS 3.5 on Sun 3/80 and SparcStation-1 ?

[Charles Hedrick]

- Can we run SunOS 3.5 on the 3/80 ? If yes, is it binary compatible
  with the version running on the 3/50s ?

No.  The 3/80 uses the 68030 memory management.  Thus portions of the
kernel are different than the kernel used on the older 68020 systems.
Even under 4.0.3, you will use a different kernel for the 3/50 and 3/80.
The 4.0.x kernel is generally upward-compatible with 3.x, so you might be
able to get away with using a 3.5 kernel on the 3/50 and a 4.0.3 kernel on
the 3/80, but using 3.5 utilties, compilers, etc.  You'd need to have
separate versions of utilities that depends upon kernel structure, e.g.
ps, pstat, etc.  4.0.3 networking is based on 4.3BSD, so some networking
things may be different as well, e.g.  ifconfig.  Presumably you would put
these things into an enlarged /usr/kvm.  I'm not sure that I recommend
this approach, but I think it could made to work with some fiddling.  I'd
try it first before buying a bunch of systems though.

- Can we run SunOS Sys4 3.2 on the SparcStation ? If yes, is it binary
  compatible with the 4/110s ?

Same answer.  The Sparcstation has its own special hardware, particularly
the SBUS, which Sys4 3.2 has never heard of.  Even under 4.0.3, there are
different kernels for the 4/110 and SS1.  Again, you may be able to use
the utilities and have only kernels and a few kernel-related programs
differ.  But it will take some experimentation to set up.

We were in a similar situation a year ago, and decided to move everything
to the newest OS.  I think I regret it.  It took a year of working with
the Sun support people to get a 4.0.1 kernel that doesn't have the various
NFS hangs and file confusion problems.  (I'm fairly sure that not all of
these fixes are in 4.0.3.)  And our 3/50's have become more or less just
terminals.  I'd be inclined to run your 3/80's and SS1's under 4.0.3, and
leave well enough alone on the older systems until 4.1 comes out.  (This
assumes that 4.1 is tested and debugged better than 4.0, and that it will
make 4MB machines usable again.  If it has the same reliability problems
as 4.0, people may want to start looking for another vendor.)  I'm using a
SS1 as a file server.  With fast external SCSI disks (we're using 780MB
H-P disks), it does quite well.  That would allow you to put together a
self- contained setup for your 3/80's and SS1's, running 4.0.3.  The only
thing that worries me about that is that I recently saw signs of the NFS
hangs on our SS1 file server.  It was running stock Sun 4.0.3c.  This
won't happen now that I've gotten source and put in all known fixes.  But
it might happen to you.  So I'd be inclined to make use of the SS1 as a
file server contingent on getting Sun to give you all known NFS and file
system fixes.