DEC PDP-10 (DECSYSTEM 2020) S/N 4224

This DECSYSTEM 2020 was donated to the Rhode Island Computer Museum by 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 LP20 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. A disk drive was modified to run on a 220VAC 30A single-phase circuit. The system now has an RM03 disk drive that came from an PDP-11/70. The RM03 is configured for 16-bit data for the PDP-11/70 and needs to be modified to work with 18 bit data for the KS10.

KS10 systems use one or more Unibus chassis for I/O.

The KS10 chassis in the 2020 contains the following boards:

Slot#

1

2

3

4

5

6

7

8

9

10

11

12

13

14

15

16

17

18

19

20

21AB

21CD

21EF

22

23

24CD

24EF

25CD

25EF

26CD

27CD

28AB

28CD

29AB

29CD

Module#

M8629

M8629

M8629

M8629

M8629

M8629

M8629

M8629

M8618

M8623

M8622

M8620

M8621

M8619

M8616

M8619

M9014

M7297

M7296

M7295

M7294YA

M5904

M688

M5904

M688

M5904

MG727

M9300

MG727

M9300

MG727

Option

MMA

MMA

MMA

MMA

MMA

MMA

MMA

MMA

MMC

CRM

CRA

DPE

DPM

UBA#3

CSL

UBA#1

RH11

RH11

RH11

RH11

RH11

RH11

RH11

RH11

RH11

RH11

Description

64KW RAM

64KW RAM

64KW RAM

64KW RAM

64KW RAM

64KW RAM

64KW RAM

64KW RAM

Memory Controller

Empty

Micro Controller

Micro Controller

Data Path

Data Path

Empty

Unibus Adapter

Empty

Console

Unibus Adapter

Empty

UNIBUS to 3 H854s

MASSBUS parity control

MASSBUS control and status

MASSBUS bus control

MASSBUS data buffer and control

MASSBUS control transceiver

UNIBUS power fail driver

MASSBUS control transceiver

UNIBUS power fail driver

MASSBUS control transceiver

Unibus Grant

UNIBUS terminator

Unibus Grant

UNIBUS terminator

Unibus Grant

The KS10. The two TU45 two tape drives are to the right. The left TU45 contains the TM03 tape controller.

The drive to the left of the CPU is a RM03. The RP06 drive is behind the RM03.

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.

The Unibus chassis in the 2020 contains the following boards:

Slot#

1

2

3

4

5

6

7

8

9U

9M

10

11U

11M

11L

12

13

14M

14L

15M

16M

17M

18U

18M

19U

20

21U

22

23

24U

24M

Module#

M9014

empty

empty

empty

M7819

M7819

M7819

M7819

M9202

MG727

empty

M9202

M7297

M7296

M7295

M7294YA

M5904

M6886

M5904

M5904

MG727

M9300

MG727

M9202

empty

M9202

M8586

M8571

M9300

M8585

Option

RH11

DZ11-A

DZ11-A

DZ11-A

DZ11-A

RH11

RH11

RH11

RH11

RH11

RH11

RH11

RH11

LP20

LP20

LP20

Description

UNIBUS to 3 H854s

8-line double-buffered async EIA with modem control

8-line double-buffered async EIA with modem control

8-line double-buffered async EIA with modem control

8-line double-buffered async EIA with modem control

Unibus Jumper

Grant

Unibus Jumper

MASSBUS parity control

MASSBUS control and status

MASSBUS bus control

MASSBUS data buffer and control

MASSBUS control transceiver

UNIBUS power fail driver

MASSBUS control transceiver

MASSBUS control transceiver

Grant

UNIBUS terminator

Grant

Unibus Jumper

Unibus Jumper

LP20 control

LP20 Data Path

UNIBUS terminator

LP20 Translation RAM