[Unix-jun72] Some discussion

Tim Newsham newsham at lava.net
Tue Apr 29 09:03:09 AEST 2008

Below I include part of an email I sent out to Brantley earlier on my 
plans.  I've been using 7ed unix and "as" so far to compile the pieces
of the source as they've become available.  I have a "sys.s" file
in the svn that defines the system calls per the u1.s file (Brantley
says the older versions of "as" had the syscall table built in):

    $ as - sys.s u0.s ux.s

and used that as a quick litmus test for syntax errors.  Now that I
am aware of apout I will probably start using the "as" from the 1972

earlier comments:
As for putting the machine together, I've put together some notes
in the svn under machine.txt.  It seems to be a pdp 11/20 with 24kbytes
ram, and rk03, rf, ttys on a dc-11, tape on tc-11.  I think all of
this should be fairly easy to set up in simh except the ttys
(and console is only used in single user according to docs).  Simh
doesnt support 24kbyte ram setting, but 32k should prob work fine.

Interestingly the kernel has a build mode ("cold") where it will
build a new filesystem on disk, so that might make bringing up
the system a little easier.  There's a boot sequence that seems a
little elaborate described in one of the 1st ed manuals, but probably
for initial bring-up it would be sufficient to just deposit all
the values in the right place with simh using a script to generate
the simh config...

If you have any suggestions, I'd love to hear them.  I've played with
pdp-11 in simh before, but a lot of this is still new to me.

Tim Newsham

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