DL10 PDP-11 Data Link

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The DL10 PDP-10/PDP-11 Interface Channel connects PDP-10 mainframes to PDP-11s used as communication front ends; up to 4 PDP-11's per DL10. It allows the PDP-10 to 'see' into the PDP-11's main memory, and vice versa (although the ability of the PDP-11 to do so is limited by the DL10's settings).

On the PDP-10 side, it connected to the PDP-10 memory bus, and also to two I/O busses (allowing it to be controlled by both processors in a multi-CPU system. So, it could be connected to KA10s and KI10s, but only to KL10s with the optional old-style I/O busses.

On the PDP-11 side, PDP-11's connected to the DL10 have a special console which has a cable which goes to the DL10, which allows the PDP-10 to start and stop the PDP-11; the PDP-11's UNIBUS runs into the DL10 and is plugged into the DL10's backplane.

Data formats

Note that the format is selected by the second octed in the word; the values used in that octet to select the byte size in the 'pointer' mode are disjoint from the values used in that octet for the other modes.

Immediate mode

Unused 0 or 7 Unused Data
00 01 02 03 04 05 06 07 08 09 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35

Indirect mode

A P 1 Unused Address
00 01 02 03 04 05 06 07 08 09 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35
A Access
0 Read or write
1 Read only
P 16-bit word position within 36-bit word
0 Bits 0-15
1 Bits 16-31
2 Bits 20-35
3 Bits 2-17

Pointer modes

P S Word count Address
00 01 02 03 04 05 06 07 08 09 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35

Bytes are left-justified inside a 36-bit word.

S Byte size
2 16
3 12
4 8
5 7
6 6

PDP-11 control and status registers

DATO 100000 (Conditions out)

Set 11 interrupt Clear 11 interrupt Set 10 interrupt Clear 10 interrupt Set nonex memory Clear nonex memory Set parity error Clear parity error Set word count overflow Clear word count overflow Error interrupt enable 11 interrupt enable Interrupt assignment
15 14 13 12 11 10 09 08 07 06 05 04 03 02 01 00

DATI 100000 (Status)

11 interrupt 10 interrupt Nonex memory Set parity error Word count overflow This port enabled Error interrupt enable 11 interrupt enable Interrupt assignment
15 14 13 12 11 10 09 08 07 06 05 04 03 02 01 00


PDP-10 standard instructions

CONO DLB,

Base address Mask for size of pointer block PDP-11
18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35

CONO DLC,

Clear DL10 Lock DL10 11 interrupt Port enable 10 interrupt 11 interrupt Port enable 10 interrupt 11 interrupt Port enable 10 interrupt 11 interrupt Port enable 10 interrupt Priority interrupt assignment
18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35

CONI DLB,

Diag Diag msyn Diag C0 Diag C1 Diag R2 Diag R1 Diag INH CYC 11-3 8K option 11-2 8K option 11-1 8K option 11-0 8K option IOC lock on ~IOC lock delay on ~IOC lock 1 out ~IOC lock 0 out 18-bit address Got DL10 locked 11 interrupt Port enable 10 interrupt 11 interrupt Port enable 10 interrupt 11 interrupt Port enable 10 interrupt 11 interrupt Port enable 10 interrupt Priority interrupt assignment
00 01 02 03 04 05 06 07 08 09 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35