This DECSYSTEM 2020 was originally installed at the University of Massachusetts, Dartmouth (formerly Southeastern Massachusetts University).
The KS10 is the smallest model in the PDP10 family of 36 bit computers manufactured by Digital Equipment Corporation. It was introduced in 1978 as a small low cost version of the KL10. It has 512 Words of Cache Memory and supports a maximum of 512 Kwords (36-bit) of memory. ADP sold a modified version of this system that supported 1024 Kwords of memory.
This machine shipped with 512 KWords of RAM memory, a master and slave pair of TU45 Tape Drives, four RP06 Disk Drives, 32 serial ports and a Line Printer interface.
The system had problems with the KS10 chassis power supply and the tape drives. The first problem with the tape drives was defective vacuum switches that detect the position of the tape in the vacuum columns. Replacement switches purchased from World Magnetics. The CPU cabinet and tape drives run on 115VAC 30A circuits. The RP06 disk drives are usually powered by 220VAC 30A three-phase circuits. The disk drive was modified to run on a 220VAC 30A single-phase circuit. I also have an RM03 disk drive from an 11/70. I need to modify this drive to work with 18 bit data.
KS10 systems use one or more Unibus chassis for I/O.
The KS10 chassis in the 2020 contains the following boards:
| Slot# |
Module# |
Option |
Description |
|
| 1 |
M8629 |
MMA |
64KW RAM |
| 2 |
M8629 |
MMA |
64KW RAM |
| 3 |
M8629 |
MMA |
64KW RAM |
| 4 |
M8629 |
MMA |
64KW RAM |
| 5 |
M8629 |
MMA |
64KW RAM |
| 6 |
M8629 |
MMA |
64KW RAM |
| 7 |
M8629 |
MMA |
64KW RAM |
| 8 |
M8629 |
MMA |
64KW RAM |
| 9 |
M8618 |
MMC |
Memory Controller |
| 10 |
|
|
Empty |
| 11 |
M8623 |
CRM |
Micro Controller |
| 12 |
M8622 |
CRA |
Micro Controller |
| 13 |
M8620 |
DPE |
Data Path |
| 14 |
M8621 |
DPM |
Data Path |
| 15 |
|
|
Empty |
| 16 |
M8619 |
UBA#3 |
Unibus Adapter |
| 17 |
|
|
Empty |
| 18 |
M8616 |
CSL |
Console |
| 19 |
M8619 |
UBA#1 |
Unibus Adapter |
| 20 |
|
|
Empty |
| 21AB |
M9014 |
RH11 |
UNIBUS to 3 H854s |
| 21CD |
M7297 |
RH11 |
MASSBUS parity control |
| 21EF |
M7296 |
RH11 |
MASSBUS control and status |
| 22 |
M7295 |
RH11 |
MASSBUS bus control |
| 23 |
M7294YA |
RH11 |
MASSBUS data buffer and control |
| 24CD |
M5904 |
RH11 |
MASSBUS control transceiver |
| 24EF |
M688 |
RH11 |
UNIBUS power fail driver |
| 25CD |
M5904 |
RH11 |
MASSBUS control transceiver |
| 25EF |
M688 |
RH11 |
UNIBUS power fail driver |
| 26CD |
M5904 |
RH11 |
MASSBUS control transceiver |
| 27CD |
MG727 |
|
Unibus Grant |
| 28AB |
M9300 |
|
UNIBUS terminator |
| 28CD |
MG727 |
|
Unibus Grant |
| 29AB |
M9300 |
|
UNIBUS terminator |
| 29CD |
MG727 |
|
Unibus Grant |
The Unibus chassis in the 2020 contains the following boards:
| Slot# |
Module# |
Option |
Description |
|
| 1 |
M9014 |
RH11 |
UNIBUS to 3 H854s |
| 2 |
empty |
|
|
| 3 |
empty |
|
|
| 4 |
empty |
|
|
| 5 |
M7819 |
DZ11-A |
8-line double-buffered async EIA with modem control |
| 6 |
M7819 |
DZ11-A |
8-line double-buffered async EIA with modem control |
| 7 |
M7819 |
DZ11-A |
8-line double-buffered async EIA with modem control |
| 8 |
M7819 |
DZ11-A |
8-line double-buffered async EIA with modem control |
| 9U |
M9202 |
|
Unibus Jumper |
| 9M |
MG727 |
|
Grant |
| 10 |
empty |
|
|
| 11U |
M9202 |
|
Unibus Jumper |
| 11M |
M7297 |
RH11 |
MASSBUS parity control |
| 11L |
M7296 |
RH11 |
MASSBUS control and status |
| 12 |
M7295 |
RH11 |
MASSBUS bus control |
| 13 |
M7294YA |
RH11 |
MASSBUS data buffer and control |
| 14M |
M5904 |
RH11 |
MASSBUS control transceiver |
| 14L |
M6886 |
RH11 |
UNIBUS power fail driver |
| 15M |
M5904 |
RH11 |
MASSBUS control transceiver |
| 16M |
M5904 |
RH11 |
MASSBUS control transceiver |
| 17M |
MG727 |
|
Grant |
| 18U |
M9300 |
|
UNIBUS terminator |
| 18M |
MG727 |
|
Grant |
| 19U |
M9202 |
|
Unibus Jumper |
| 20 |
empty |
|
|
| 21U |
M9202 |
|
Unibus Jumper |
| 22 |
M8586 |
LP20 |
LP20 control |
| 23 |
M8571 |
LP20 |
LP20 Data Path |
| 24U |
M9300 |
|
UNIBUS terminator |
| 24M |
M8585 |
LP20 |
LP20 Translation RAM |
This is the outside and inside of the defective LH Research power supply for the KS10 chassis.
This is the inside of the TU45 tape drive. The large white object it the vacuum pump.
This is the outside and inside of the TM03 Massbus interface located in the bottom of the master TU45 tape drive. The power supply for the Massbus interface is to the left of the TM03.
