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

Noel Chiappa jnc at mercury.lcs.mit.edu
Sat Sep 26 08:08:21 AEST 2020


    > From: Paul Riley

    > I have two RLV-12/RL02 emulator boards I had made from Peter Schranz's
    > design (5volts.ch). They take an SD card

Ah, you're all set, then - doubly so, in fact. Not only do you have reliable
mass storage, but you should be able to put the Unix filesystem on an SD card,
to get the bits into the machine.

I'm not familiar with that board, but it sounds pretty good; QBUS<->SD. I
don't know how that board uses the SD card, in terms of where it keeps the
RL02 image, but if you can find that out, SD<->USB3 adaptors are cheap and
plentiful, and it shouldn't be too hard to load the disk image into it using
one of them. (For the QSIC, I found a 'dd' for Winsdoze and used that to write
the disk image onto the SD card.)


    > I don't have any PROMs other than what would be on the '03 or '23+
    > boards now.

Not a problem: if you hook up the -11's console to another computer, you
can download a bootstrap into it over the serial line, using the -11's ODT.
(There's a page here:

  http://gunkies.org/wiki/Running_an_LSI-11_from_Unix_V6

which talks briefly about how to do that. Things like PDP11GUI can do it too,
I think.) I don't use an RK bootstrap in ROM to boot from the emulated RK11 on
the QSIC; I just load in a short RK bootstrap. I don't know of one lying
around for the RL11, but one would be trivial to whip up.


Speaking of booting, I have Mini-Uix booting under an -11/05 simulator
(Ersatz-11); I used the RK image from here:

  http://www.tavi.co.uk/unixhistory/mini-unix/munixrks.zip

and it just started right up. So that's the big hurdle; been busy with other
stuff, but I'll work on getting it to boot on an '03 'soon'.

You probably want to do the same; having it running under a simulator will
make it easy to build new OS images, e.g. for a system with RL02's. Build the
new system, name it 'rlmx', copy the simulator disk image into the SD card,
and away you go.


Oh, I recently realized how to make a  bit more room on an -11/03: most
DEC small QBUS memory cards allow you to use half the 'I/O page' for memory,
if you need it. I.e. instead of having 56KB of memory, and 8 KB of
address space for device registers (a lot more than is really needed), the
memory can be configured to be 60KB of memory.

It can be a bit of a hassle to use it; to have more room for the OS (for more
drivers, or disk buffers, or whatever), some pieces of Mini-Unix need to be
recompiled, to move up the address where user processes are loaded. Larger
user processes are the same thing; they aren't automatically enabled when
there's more memory, you have to change a config file, recompile some things,
and build a new system.

What kind of memory card(s) do you have for the -11/03?

     Noel




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