Data bus:	50-pin SCSI interface
Size:	4" x 5.75"
Hard drive supported:	Up to two ST506/412 MFM drives in 3120A, and up to two ST506/412 RLL 2,7 drives in 3127A
Floppy drives supported:	None

CONNECTIONS
Function	Location
50-pin SCSI interface	J1
34-pin MFM disk control connector	J2
20-pin data cable connector	J3
20-pin data cable connector	J4
DC power connector	J10

SCSI ADDRESS
SCSI ID		W1	W2	W3
»	0	open	open	open
»	1	closed	open	open
»	2	open	closed	open
»	3	closed	closed	open
»	4	open	open	closed
»	5	closed	open	closed
»	6	open	closed	closed
»	7	closed	closed	closed

USER CONFIGURABLE SETTINGS
Function		Location	Setting
»	SCSI parity enabled	W4	closed
»	SCSI parity disabled	W4	open
»	Factory configured - do not alter	W12/1-3	N/A
»	Factory configured - do not alter	W13/1-3	N/A
»	Factory configured - do not alter	W14/1-2	N/A
»	TRMPWR supplied by board (3127A)	W15/pins 1 & 2	closed
»	TRMPWR supplied by SCSI bus (3127A)	W15/pins 2 & 3	closed
»	Factory configured - do not alter	W17/1-3	N/A
Note: Location of W15 pin 1 is unidentified.

SECTOR CONFIGURATION
Bytes/Sector		Sector/Track	W5	W6
»	512	17	open	closed
»	256	32	closed	open
	512 (3120A)	18	open	open
	532 (3127A)	17	open	open
»	1024	9	closed	closed
Note: Location of W6 is unidentified.

TERMINATION POWER - 3120A
Function		W11/1	W11/2	W11/3
»	TRMPWR supplied by board	open	closed	closed
»	TRMPWR supplied by SCSI bus	closed	closed	open