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 <cctalk@classiccmp.org> > 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 >
