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 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.

This machine has 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.

Currently the system has problems with the KS10 chassis power supply and the tape drives. The first problem with the tape drives is defective switches that detect the position of the tape in the vacuum columns. Replacement switches are being manufactured by 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. We should be able to rewire the disk drives to run on 220VAC 30A single-phase circuits. Until the drives are rewired the system will be run with a RM03 disk drive which is powered from a 115VAC 15A circuit.

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 e
2
3
4
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
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 ctl.
14M    M5904    RH11 MASSBUS control transceiver
14L    M688     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
19M    MG727         Grant
20
21U    M9202         Unibus Jumper
21
22     M8586    LP20 LP20 control
23     M8571    LP20 ?
24U    M9300         UNIBUS terminator
24M    M8585    LP20 ?

These are outside and inside views 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 in the TU45 tape drive. The power supply for the Massbus interface is to the left of the TM03.