DL10 PDP-11 Data Link
The DL10 PDP-11 Data Link 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 up to two PDP-10 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 Memory and I/O busses (provided by the DMA20 Memory Bus Adapter and DIA20 IBus Adapter respectively).
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.
The DL10 is used in the DN87 Universal Synchronous/Asynchronous Communications Front End Subsystem.
There is little remaining DL10 documentation, alas; see below for links to what exists online.
Contents
Data formats
Note that the format is selected by the second octet 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 | Action of 1s | 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 | Standard interrupt | 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 |
External links
- BOOT11 - PDP-11 Bootstrap From PDP-10 - contains general description of the DL10 in section 4.0
- KL10-Based Physical Description - the DL10 is covered in Sections 1.8
- DECsystem-10 System Reference Manual - documents the PDP-10's DL10 control instructions in Appendix C (on pp. 365-368 of the PDF)
- DN87 Field Maintenance Print Set - contains complete engineering drawings for the DL10 (on pp. 100-212 of the PDF)