[TUHS] Work I've done with a PDP-11 simulator

Noel Chiappa jnc at mercury.lcs.mit.edu
Sun May 11 13:13:29 AEST 2014

    > From: Gregg Levine <gregg.drwho8 at gmail.com>

    > By Shoppa disk do you mean, Shoppe disk

The root pack (linked to from my page):


It contains lots of V6 goodies - but not, alas, source for most of them. (E.g.
I had to disassemble the RL bootstrap(s) from it.)

    > I've been trying to figure out how to attach them to the E11 one to
    > bring the whole thing up.

The others are junk (see below). To boot up the root pack (I don't think I
did this at any point; I've always mounted it as a subsidiary drive) you'd
need to say:

  mount dl0: unix_v6.rl02 /RL02

and then:

  boot dl0:

The disk has a working RL bootstrap in block 0, it should boot OK. Then you
get to take your pick of which unix to boot! There are 7 to chose from:

  77 -rwxrwxr-x  1 root    38598 Aug 22  1984 oldunix
  77 -rwxrwxr-x  1 root    38504 Jul 19  1984 oldunix.25.7
  77 -rwxrwxr-x  1 root    38568 Feb 20  1985 unix
  74 -rwxrwxr-x  1 4       36956 Mar  9  1983 unix.jones
  69 -rwxrwxr-x  1 root    34408 Aug 16  1983 unix.mlab
  76 -rwxrwxr-x  1 4       38316 Sep  3  1982 unix.rxrl
  68 -rwxrwxr-x  1 root    33958 Jun  6  1983 unix.tmp        

and I have no idea how they all differ - or what each one expects to use for
a root device and swap device.

Looking at 'unix', it gives both rootdev and swapdev as '01000' (which is
probably the RL, I'm too lazy to grovel around in bdevsw and make sure). The
super block reports 19000 as the size of the file system, and sure enough,
swplo is reported as 045070 (19000), and nswap as 02710 (1480). So it's
probably set up to run and swap on RL/0.

    > and any of the set of disks that are in the distributions portion of
    > the site with his name on them?

All of the other disks in the V6 folder with his name on it:


are junk; here's a brief rundown on each one:


All very similar to the 'unlabeled' disk (below) - lots of random user files
for biology stuff, little if anything of any use/interest.

There is a file which isn't listed in the README:


It looks like another /user disk, full of random biology stuff; nothing
interesting except a copy of a nice-looking Kermit written in C (by someone
at Columbia, IIRC).


An RL01 pack (the others are all RL02's); it has a boot block with PDP-11
code in it; I mounted it on a simulator and booted it, and it says it's an
RSX-11M V3.2 disk.


This is also an RSX pack (I think), but when I tried to boot it, it said
know how to mount disks under RSX-11 I left it at that.


This does indeed seem to be something that was used for disk diagnostics: the
boot block contains gubble, including (in the first RL11 block) lots of words
with all ones, and a lot of 52525's.


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