TSX-Plus Password Hacking & Other PDP-11 Issues

From: Rick Bensene <rickb_at_bensene.com>
Date: Tue May 6 11:57:01 2003

Hello, everyone,

I recently became the owner of a nice PDP 11/34A system. It has 248Kb
of parity RAM,
programmer's panel, RL11 w/1 RL01, RK11 w/3 RK05's, RX211 w/dual RX02
drives, EAE, DZ11, and standard console port w/RTC interrupt generator.

I've got it so that it'll boot RT-11 V5.3 from one of the RL01 packs
that I got with the
machine. It appears that this pack also has the TSX-Plus (can't recall
the version,.. 5.1A?)
multi-user extension for RT-11 installed. Problem is, I can't login
when I start up TSX-Plus
because I don't know the PPN's or passwords.

There's a file called ACCESS.TSX that appears to be the
username/password database, but
it appears to be stored in encoded form...I've tried dumping it in
RAD50, as well as in
HEX, OCTAL, and ASCII, and haven't been able to make heads nor tails of

Does anyone know the structure of this file, and how it is encoded? I'd
like to be able
to get a few ports running on the DZ11 and see how it performs in a
timeshared RT-11

My long term goal is to get RSTS/E up and running on the machine.
According to some of
the docs, it's possible to run RSTS/E on an 11 with 1 RL01 and 2 RK05's,
which I should
be able to do, though I've not hooked up the RK11 (it has the RK11's
installed, but I've removed the UNIBUS jumper that connected the main
to the RK11's backplane and installed the terminator in its place) and
RK05's as yet.

Another issue I've got is that the machine gets unstable when I put the
RX211 controller
in. Sometimes the system behaves with it in place, other times, it
I have made sure that the NPG jumpers are removed on the backplane slots
that the RL11 and
RX211 are installed in (the last two slots on the 9 slot backplane).
The UNIBUS is properly terminated. When the system behaves with the
RX11 in place, I can intermittently
read/write floppies, but, it's intermittent, and when it's not working,
the whole machine
gets pretty confused. The RX211 has its switches set to the standard
settings as
documented in the RX211 uuser's guide, and the interrupt priority header
is the standard
one also. I'm a little baffled. The backplane is full with the RX211
installed. The
+5V power on the backplane is clean, and running at +4.98V. When I
remove the RX211 and
insert a NPG/Interrupt Grant jumper, the machine runs beautifully. Is
this a sign of
a sick RX211, or some kind of bus loading problem?

Any help that all you DEC fans can give would be greatly appreciated.

Thanks in advance,

Rick Bensene
The Old Calculator Web Museum
Received on Tue May 06 2003 - 11:57:01 BST

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