KT11-D Memory Management Unit
The KT11-D Memory Management was an option for the KD11-A CPU of the PDP-11/40 which provided memory management. It did not provide the full PDP-11 Memory Management, but the simplified subset; in fact, the KT11-D is the archetype for that subset.
It was a hex card (M7236) which plugged into a dedicated, pre-wrired slot in the CPU's backplane. DEC documentation indicates that the KT11-D required the KJ11-A Stack Limit Register option (see e.g. EK-11040-TM-002, pg. 4-22) but this may just be an artifact of DEC PDP-11 software.
To install the KT11-D, in addition to installing the card in the backplane slot, a number of jumpers on other CPU cards have to be adjusted. Two capacitors also have to be installed, to modify timing delays in the CPU.
- KT11-D Memory Management Option Manual (DEC-11-HKTDA-B-D)
- KT11-D memory management option user's manual (EK-KT11D-OP-001)
- KT11-D memory management option engineering drawings
- Protection & Relocation for the PDP-11/40 - interesting design memo