DEC Digital PC 3500 System Reference Manual page 149

Adding Mass Storage Devices
Figure
Legend
A
B
C
D
E
F
G
H
6-30
Component
SCSI hard disk drive or other device
Power connection
Single-ended active terminator
SCSI drive connectors
SCSI adapter connector (50-pin narrow)
External SCSI connector (68-pin wide)
Power supply
SCSI adapter connector (68-pin wide)