The PDP-11/24

PDP-11/24 CPU box

The PDP-11/24 was introduced by DEC in 1981, which means that it is just as old as i am ;-)
This one is mounted in a BA11-L mounting box which contains just one 9-slot Unibus backplane which got slot 1 and 2 specially wired for the 11/24 CPU module (M7133) and its Unibus Map option (M7134). When i got it, the machine complained about bad voltages by blinking the DC ON light, but this was fixed with disconnecting the Unibus extender that comes in a second BA11-L. Unfortunately, i didn't get this machine to run because its console SLU seems broken. It can send characters to the terminal, but it cannot receive. I guess that it either was modified in some strange way (there are weird cables soldered on the module, one conductor on the board is cut) or that it is just plain broken.

Update: I found out that the chip in location E120 (a differential line receiver) on the CPU board was broken and replaced it, now the console SLU works.

Currently, there are the CPU module, the Unibus Map option module and two 512KW RAM boards in the CPU backplane.


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