Piedinature - Pinouts
SCSI-II External Hi D-Sub (Single-ended)

Reference and Sources:

50 PIN HI-DENSITY D-SUB FEMALE (At the controller & devices).

50 PIN HI-DENSITY D-SUB MALE (To the cable).

50 PIN HI-DENSITY D-SUB FEMALE at the controller & devices.
50 PIN HI-DENSITY D-SUB MALE at the cable.

Pin	Name	Dir	Description
1-25	GND	------	Ground
26	DB0	IN/OUT	Data Bus 0
27	DB1	IN/OUT	Data Bus 1
28	DB2	IN/OUT	Data Bus 2
29	DB3	IN/OUT	Data Bus 3
30	DB4	IN/OUT	Data Bus 4
31	DB5	IN/OUT	Data Bus 5
32	DB6	IN/OUT	Data Bus 6
33	DB7	IN/OUT	Data Bus 7
34	PARITY	IN/OUT	Data Parity (odd Parity)
35	GND	------	Ground
36	GND	------	Ground
37	GND	------	Ground
38	TMPWR	IN/OUT	Termination Power
39	GND	------	Ground
40	GND	------	Ground
41	/ATN	IN	Attention
42	n/c	-	Not connected
43	/BSY	IN/OUT	Busy
44	/ACK	IN	Acknowledge
45	/RST	IN/OUT	Reset
46	/MSG	OUT	Message
47	/SEL	IN/OUT	Select
48	/C/D	OUT	Control/Data
49	/REQ	OUT	Request
50	/I/O	OUT	Input/Output

Note: Direction is Device relative Bus (other Devices).

For more informations, references and sources go to

Piedinature - PinoutsSCSI-II External Hi D-Sub (Single-ended)