� Internal SCSI Port (50-Pin Header)
� External SCSI Connector (High-density 50-pin) See External
SCSI Connector.
� All odd pins are grounds, except for pin 25, which is unused.
�� Pin 2: *Data 0
�� Pin 4: *Data 1
�� Pin 6: *Data 2
�� Pin 8: *Data 3
� Pin 10: *Data 4
� Pin 12: *Data 5
� Pin 14: *Data 6
� Pin 16: *Data 7
� Pin 18: *Parity
� Pin 20: Ground
� Pin 22: Ground
� Pin 24: Ground
� Pin 26: Terminator Power
� Pin 28: Ground
� Pin 30: Ground
� Pin 32: *ATN
� Pin 34: Ground (Unused?)
� Pin 36: *BSY
� Pin 38: *ACK
� Pin 40: *RST
� Pin 42: *MSG
� Pin 44: *SEL
� Pin 46: *C/D
� Pin 48: *REQ
� Pin 50: *I/O
�
External SCSI Connector (DB25 Macintosh-Type Female Pseudo-SCSI)
(Note: This is by far the most common style of DB25 SCSI connector.
Most�[probably all] Amiga SCSI interfaces with DB25 connectors--like the
A2091--use this pin-out.)
�� Pin 1: *REQ
�� Pin 2: *MSG
�� Pin 3: *I/O
�� Pin 4: *RST
�� Pin 5: *ACK
�� Pin 6: *BSY
�� Pin 7: Ground
�� Pin 8: *Data 0
�� Pin 9: Ground
� Pin 10: *Data 3
� Pin 11: *Data 5
� Pin 12: *Data 6
� Pin 13: *Data 7
� Pin 14: Ground
� Pin 15: *C/D
� Pin 16: Ground
� Pin 17: *ATN
� Pin 18: Ground
� Pin 19: *SEL
� Pin 20: *Parity
� Pin 21: *Data 1
� Pin 22: *Data 2
� Pin 23: *Data 4
� Pin 24: Ground
� Pin 25: Terminator Power
�
External SCSI Connector (DB25 Future Domain-Type Female Pseudo-SCSI)
(Note: This is a rare alternate standard for the DB25 connector. It
was only used on the Future Domain TMC-830/845 and TMC-850/860/885,� and
is included here in case you end up with a cable meant for these boards.)
�� Pin 1: Ground
�� Pin 2: *Data 1
�� Pin 3: *Data 3
�� Pin 4: *Data 5
�� Pin 5: *Data 7
�� Pin 6: Ground
�� Pin 7: *SEL
�� Pin 8: Ground
�� Pin 9: Terminator Power
� Pin 10: *RST
� Pin 11: *C/D
� Pin 12: *I/O
� Pin 13: Ground
� Pin 14: *Data 0
� Pin 15: *Data 2
� Pin 16: *Data 4
� Pin 17: *Data 6
� Pin 18: *Parity
� Pin 19: Ground
� Pin 20: *ATN
� Pin 21: *MSG
� Pin 22: *ACK
� Pin 23: *BSY
� Pin 24: *REQ
� Pin 25: Ground
�
External SCSI Connector (Centronics 50-Pin Female)
� Pins 1-12 and 14-25 are grounds.
� Pin 26: *Data 0
� Pin 27: *Data 1
� Pin 28: *Data 2
� Pin 29: *Data 3
� Pin 30: *Data 4
� Pin 31: *Data 5
� Pin 32: *Data 6
� Pin 33: *Data 7
� Pin 34: *Parity
� Pin 35: Ground
� Pin 36: Ground
� Pin 37: Ground
� Pin 38: Terminator Power
� Pin 39: Ground
� Pin 40: Ground
� Pin 41: *ATN
� Pin 42: Ground (Unused?)
� Pin 43: *BSY
� Pin 44: *ACK
� Pin 45: *RST
� Pin 46: *MSG
� Pin 47: *SEL
� Pin 48: *C/D
� Pin 49: *REQ
� Pin 50: *I/O
�
2.5-Inch Drive SCSI Connector (40-Pin Header)
Pins 1, 2, 39, and 40 are +5V. Pins 3, 4, 37, and 38 are ground returns for the +5V supply. Pins 5, 7, 9, 11, 13, 15, 19, 21, 23, 27, 31, and 35 are signal grounds. Pin 17 is used as a connector key and should not be present.
�� Pin 6: *Data 0
�� Pin 8: *Data 1
� Pin 10: *Data 2
� Pin 12: *Data 3
� Pin 14: *Data 4
� Pin 16: *Data 5
� Pin 18: *Data 6
� Pin 20: *Data 7
� Pin 22: *Parity
� Pin 24: Terminator Power
� Pin 25: *ATN
� Pin 26: *BSY
� Pin 28: *ACK
� Pin 29: *RST
� Pin 30: *MSG
� Pin 32: *SEL
� Pin 33: *I/O
� Pin 34: *C/D
� Pin 36: *REQ