[TUHS] Fwd: Choice of Unix for 11/03 and 11/23+ Systems

Noel Chiappa jnc at mercury.lcs.mit.edu
Tue Sep 22 05:37:28 AEST 2020


    > From: Paul Riley

    > Using LSX on the 11/03... Will LSX handle cards with multiple serial
    > ports?

Ah, I just read this carefully; LSX only supports a single user at a time, so
there's no use to multiple serial lines? (But see below.) (I thought Heinz'
reply message to this referred to Mini-Unix, which does suppport multiple
users, but on reading it again I see it does not.)


If you want multiple users on an -11/03, Mini-Unix would be an option; it
doesn't support the -11/03 'out of the box', but looking at it, it shouldn't
be too hard. (Heinz mentioned that it had been done before.) Change all cases
of 'mov xx, PS' in mch.s:

  https://minnie.tuhs.org//cgi-bin/utree.pl?file=Mini-Unix/usr/sys/mxsys/mch.s

to 'MTPS xx' (PS access needs a special instructtion in the /03); that might
be all you need to do. (Installing a KEV11-A, so you can avoid using the
instruction emulation package for EIS instructions would be nice, but
apparently isn't required.)


If Mini-Unix supports multiple users, it ought to be possible to do the same
with LSX. (I'm not sure what the rationale was for making LSX single-user:
perhaps the RX was too slow; perhaps there was no need in their use case;
etc.)

But it would probably be more work than going the Mini-Unix route; e.g.
to start with, init only supports a single user:

  https://minnie.tuhs.org//cgi-bin/utree.pl?file=LSX/src/init.c

and the tty driver:

  https://minnie.tuhs.org//cgi-bin/utree.pl?file=LSX/sys/tv.c

only supports a single line. One could cross-port the needed 'stuff' from
Mini-Unix, but it'd probably be easier to do the Mini-Unix -11/03 conversion.

	   Noel


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