I was lucky enough to pickup a PDP-11/70 last week, thanks to the generosity of a fellow collector.
Here are some pictures of the racks (vertical):
… and more pictures (horizontal):
Main Processor Box
The standard decal showing the modules in a PDP-11/70 is shown below (this is Figure C-3 from the Maintenance and Installation Manual):
Figure 4-20 of the Maintenance and Installation Manual shows a more detailed view of the backplane, viewed from the wirewrap side:
Based on a quick check, my 11/70 seems to be pretty much complete.
This machine has the KB11-C CPU, as evidenced by the M8123 in Slot 9. The earlier KB11-B processor would have an M8133 in Slot 9.
There’s no floating-point option fitted to this 11/70.
The PDP-11/70 processor box has capacity for the following peripheral controllers:
- 4 x RH70 Massbus Controllers (each controller takes up 4 slots)
- 5 x SPC Slots
There are no RH70 Massbus Controllers installed in this 11/70.
The peripheral controllers actually installed in this 11/70 are:
- Emulex SC72 SMD controller (in the Massbus Controller C slots)
- RL11 RL01/RL02 Disk Drive Controller
- Emulex TC13 Tape Coupler (emulates TS11)
- DL11-W SLU & Real Time Clock
Here’s the full list of modules in the processor box:
|M9312||Unibus Terminator and Bootstrap Loader and Diagnostic|
|2-5||Empty||Floating Point Processor|
|6||M8130||11/70 Data Paths|
|7||M8131||11/70 General Registers and ALU Control|
|8||M8132||11/70 IR Decode and Condition Codes|
|9||M8123||11/70 ROM & ROM Control, FP11-C compatible|
|10||M8134||11/70 Processor Data and Unibus Registers|
|11||M8135||Trap and Miscellaneous Control|
|12||M8136||Unibus and Console Control|
|14||M8137||System Address Paths|
|15||M8138||System Status Registers|
|16||M8140||System Descriptor / Console Cables|
|21||M8145||Cache Data Paths|
|24-27||Empty||RH70 Controller A – Spare|
|28-31||Empty||RH70 Controller B – Spare|
|32||SU7010406||Emulex SC72 – C Board|
|SU7010404||Emulex SC72 – CST Board|
|34||SU7210403||Emulex SC72 – B Board|
|35||SU7210401||Emulex SC72 – A Board|
|36-39||Empty||RH70 Controller D – Spare|
|40||M7762||SPC Slot – RL11 RL01/02 Disk Drive Controller|
|41||G7273||SPC slot – Spare|
|42||TU131041||SPC Slot – Emulex TC13 Tape Coupler (emulates TS11)|
|43||G7273||SPC slot – Spare|
|44||M7856||SPC slot – DL11-W SLU & Real Time Clock|
- there are G727 grant continuation cards in 27D and 31D and 39D
- there are G7273 grant continuation cards in 41C-D and 43C-D
- there is an M9302 Unibus terminator in 44A-B
The memory frame is mounted just above the CPU Mounting box.
This system is fitted with 512KB of memory (2 x M8728 256KB boards are fitted).
Figure 3-30 of the Manual shows the standard configuration of the Memory Frame:
The Memory Frame is populated as follows:
|2-8||Empty||Storage Array (even) #14-#2|
|9||M8728||Storage Array #0: 256KB|
|10||M8161||0 Control B (Data & ECC)|
|11||M8160||0 Control A (Timing & Control)|
|16||M8160||1 Control A (Timing & Control)|
|17||M8161||1 Control B (Data & ECC)|
|18||M8728||Storage Array #1: 256KB|
|19-25||Empty||Storage Array (odd) #3-#15|
Interestingly the same memory array boards (M8728) were also used in the VAX-11/780.
This Expansion Unit is a model H960-D. It has another sticker on it identifying it as a Box Type of “BA11-FE”.
It has a number of 4-slot and 9-slot back planes in it. I’m not sure yet which of these are “SPC” back planes, and which are special purpose back planes.
Here’s the list of the back planes and their contents:
Backplane 1 (4 slot):
|Slot 1 A-B||M9680||“DR11-B Test Board”|
|Slot 1 C-F||M7219||“Bus Interface”|
Slot 2: A-B empty, C: M208, D: M208, E-F: M7821
Slot 3: A: Small paddle board feeding power in, B: M205, C: M611, D: M611, E: M112, F: M112
Slot 4: A-B: M920 bridge, C-D: M7229, E: M116, F: M239
Backplane 2 (9 slot):
Slots 1 & 9: M920 bridge in A-B
Slots 2, 4, 6 & 8: G727A grant continuity card in D
Slots 3, 5 & 7: Completely empty (previous boards removed).
Backplane 3 (4 slot)
Slot 1: A-B: M920
Slot 2 & 3: D: G727A
Slot 4: Strange hex-width M7084, with small paddle-board above A-B bridged to M9202 in Backplane 4. Labelled “BUS REPEATER FOR PDP11” and “CSS MUNICH SSM 0235”. Also marked “DB11-H”. Has a “digital” sticker on Side 1.
Backplane 4 (9 Slot)
Slot 1: A-B: M9202 bridge from Backplane 3
Slots 2, 5, 8: M7814 (Multiplexer?) [Hex Width]
Slots 1, 3, 4, 6, 7 & 9 C: G727A
Slot 9 A-B: M920 to Backplane 5
Slot1 A-B: M920 from Backplane 4
Slots 2, 4 & 6: M7814
Slots 1, 3, 5, 7, 8 & 9 D: G727A
Slot 9 A-B: M9302 terminator