No I put together an RX02 with an RX01 controller on my bigger computer
to format a special disk. It can only use RX01 formatted disks, and to
make a boot disk you need the PD.SYS driver and to copy/boot the PD
driver to the boot block.
And yes, the switch on the back is broken. How did you guess :-) For
awhile I used it in the 80's as a mini BBS with MUBasic and a little
program I ran on top of that. Technically it did... work.. ish.
C
On 4/26/2020 4:42 PM, Zane Healy wrote:
Somehow I like the term “Boat Anchor” to describe the PDT-11/150. I’ve had one
for well over 20 years. At a bare minimum, it needs the on/off switched
replaced, as it’s broken off. Is that the disk that came with yours? I like
how it’s all games. :-)
I can’t remember, are these disks formatted strange?
Zane
On Apr 26, 2020, at 1:33 PM, Chris Zach via cctalk <[email protected]>
wrote:
So I've had a boat anchor pdt11/150 here for awhile. It's probably one of the
weirdest pdp11s ever built: An 11/03 CPU ish, six serial ports, ish, and a pair
of RX01 drives.
Ish.
The trick is the system is very closed in: There are 4 boards inside with a lot
of early microprocessors to do the IO instead of a real Q bus. The bottom board
is a controller that is sort of like an RX01 but instead of using the DX:
driver it uses a special PD: driver. The CPU connects to this with a 14 pin DIP
ribbon cable, and on the back of the CPU module is a 64kb memory module and a
serial module that has a console, printer, modem and three additional serial
ports that are their own thing.
Problem with this one was that it would not come up. Serial tests seemed to
fail using an error code of waiting for input which didn't make a lot of sense.
So today I decided to pull the serial board and see if I could swap the UARTs.
I quickly figured out the problem: The serial board "connects" to the main
board by two sets of bars with three screws each that hold the board to an
interconnecting header that sends the signals. As soon as I loosened the screws I
realized that the header isn't connecting to pins on either board, it literally presses
against pads on the boards that complete the circuit. Nothing but pressure and
springiness holds it together. No screw, pin and socket, anything.
With that I cleaned off the headers and wiped down the pads on the boards till
they shined like the top of the chrystler building. I then reassembled and
torqued the screws down evenly, finishing with the center screw first followed
by the outside screws. It is to note that the hinges that hold the CPU and
memory/serial boards to the body of this thing attach to the bottom of those
screws so when you open it up you are flexing the assembly and probably
stretching the screws a bit. Which results in bad contact...
Plugged it in and all is well.
RT-11SJ (S) V05.01C
.DIR SY:
SPCINV.SAV 10 21-Mar-1989 OTHELO.SAV 45 21-Mar-1989
SPCINV.DAT 1 21-Mar-1989 TODAY .SAV 20 22-Feb-1988
DECMAN.SAV 14 21-Mar-1989 SPACWR.SAV 13 21-Mar-1989
STRTRK.SAV 54 21-Mar-1989 SWAP .SYS 26P 27-Jul-1984
RT11SJ.SYS 64P 19-Jun-1988 TT .SYS 2P 19-Jun-1988
PD .SYS 3P 19-Jun-1988 DX .SYS 4P 21-Jan-2000
PIP .SAV 30P 21-Jan-2000 DUP .SAV 52P 21-Jan-2000
DIR .SAV 20P 21-Jan-2000
15 Files, 358 Blocks
128 Free blocks
Another little DEC mystery solved. One odd thing about these: There are only
four chip slots for the CPU and microcode, but one of the carriers has two dies
on it so the system *does* have EIS and FIS instructions. Why not...
Chris
