New 11/24, what to do first? More info.

Gooijen, Henk henk.gooijen at
Sat Jan 7 16:28:14 CST 2006

Hit the Send button too fast.
That is a nice complete machine you have, Charles.
I remember paying just UK £300 for only that RH11.
Start looking for a MASSBUS tape drive, or disk drive,
** if you have plenty room and power **. The MASSBUS
stuff is not for the weak persons. All my MASSBUS stuff
is heavy, both in weight and in power consumption!
MASSBUS cables are approx. 30 - 40 mm thick ...
I have some MASSBUS stuff in the 11/70 page on my site.
As said, "I know notting" about the 11/24.
- Henk, PA8PDP.


Van: cctalk-bounces at namens Charles
Verzonden: za 07-01-2006 21:30
Aan: cctalk at
Onderwerp: New 11/24, what to do first? More info.

>Contacts or loosen screws can fly through the BA-box in case of your 11/24
> during transport and can provoke short circuits while powering up.
>Always inspect your machine carefully, watch out for loosen parts and check
>the configuration of your system BEFORE aplying power to it.

Don't worry, Pierre, I did all that as soon as I got it home, well
before plugging it in. But thanks for the reminder.

I have now inventoried the cards and have the following:

1 M7133 KDF11-UA 11/24 CPU with line clock and 2 SLU
1 M7134 KT-24 Unibus map, extension to 22 bits
1 M8743 (ECC RAM, either 512 Kb or 1 Mbyte)
2 M8722 (ECC Memory either 128 Kb or 256 Kb each)
1 M8188 FPF11 floating point processor
1 M7762 RL11 disk controller RL01/02
1 M7258 LP11 printer controller
1 DSD A2130-6 <---------- (what is this? Floppy controller?)
4 M7819 DZ11-A eight RS232 ports each

1 M920 Unibus connector
1 M7297 RH11 MASSBUS Parity Control
1 M7296 RH11 MASSBUS Control & Status Registers
1 M7295 RH11A MASSBUS Bus Controller
1 M7294 RH11 MASSBUS Data Buffer and Control
3 M5904 RH11 MASSBUS Control Transceivers
1 M9300 Unibus terminator
1 M9312 Bootstrap Terminator

According to the PDP11 Bus Handbook the Massbus is for
transferring blocks of data at high speed (between mass storage
devices like disks or tapes?)

When I flip the BOOT switch the front panel RUN light comes on
briefly and goes out again. Similar behavior to the 11/23+ when it
enters ODT mode. There is a green LED on each MOS memory board
which is lit, and a row of three (status?) LED's on the CPU, the
rearmost staying lit and the other two dark. Time to RTFM I guess
:) but I'll bet I can hook up a terminal to the SLU on the CPU
board and have it talk to me!

I wonder, since there is an RL controller card,


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