[TUHS] Unix on an 11/23 (Was: Work I've done with a PDP-11 simulator)

Noel Chiappa jnc at mercury.lcs.mit.edu
Tue May 20 12:19:13 AEST 2014

    > From: asbesto <asbesto at freaknet.org>

    > Just in these days we restored a PDP-11/23PLUS here at our Museum! :)
    > ...
    > CPU is working

That is good to hear! You all seem to have been very resourceful in making
the power supply for it!

    > and we're trying to boot from a RL02 unit :)

Is your RL02 drive and RLV11 controller all working? Here are some
interesting pages:


from someone in Germany about getting their RL11 and RL02 to work.

Also, when you say "boot from an RL02", what are you trying to boot? Do you
have an RL02 pack with a working system on it? If so, what kind - a Unix
of some sort, or some DEC operating system?

    > From: SPC <spedraja at gmail.com>

    > I'll keep a reference of this message and try it as soon as possible...

Speaking of getting Unix to run on an 11/23 with an RL02... I just realized
that the hard part of getting a Unix running, for you, will not be getting V6
to run on a machine without a switch register (which is actually pretty easy
- I have worked out a way to do it that involves changing one line in
param.h, and adding two lines of code to main.c).

The hard part is going getting the bits onto the disk! If all you have is an
RL02, you are going to have to load bits into the computer over a serial line.

WKT has done this for V7 Unix:


but V7 really wants a machine with split I/D (which the /23 does not have). I
guess V7 'sort of' works on a machine without I/D, but I'm not a V7 expert,
so I can't say for sure.

It would not be hard to do something similar to the VTServer thing for V6,
though. If you would like to go this way, let me know, I would be very
interested in helping with this.

Also, do you only have one working RL02 drive, or more than one? If you only
have one, you will not be able to do backups (unless you have something else
connected to the machine, e.g. some sort of tape drive, or something).


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