GST, Inc. - IBM System p, p5, System i, i5, OpenPower and TotalStorage Experts.

HD68 Male

HD68 Female

Mini HD68 (Ultra wide SCSI-3/ Ultra2 LVD SCSI/ wide Differential SCSI both internal and external). The internal and external connectors appear to be different, but they are the same basic connector. The easy way to tell the difference between an HD50 and an HD68 (unless you want to count those tiny little pins) is to measure them. HD50 is about 1 3/8 (36mm) , and the HD68 is about 1 7/8 (47mm).

VHDCI

VHDCI male

VHDCI female

VHDCI 0.8mm HPCN68 male- Sometimes called SCSI-5. Very popular in new tape SCSI cards.

Centronics

Centronics male

VHDCI female scsi connector

Centronics female

Centronics C50 sometimes referred to as CN50, Cent50 (External connector on many SCSI-1 and some SCSI-2 Controllers) The controller connector and peripherals connectors should be females, and the cables male.

Listed below are the SCSI types bus lengths, devices supported, etc.

SCSI Terminology	Bus Speed, Max MB/s	Bus Width, bits	Max Length - Meters ⁽¹⁾			Max. Device Support
SCSI Terminology	Bus Speed, Max MB/s	Bus Width, bits	SE	LVD	HVD	Max. Device Support
SCSI-1⁽²⁾	5	8	6	⁽³⁾	25	8
Fast SCSI⁽²⁾	10	8	3	⁽³⁾	25	8
Fast Wide SCSI	20	16	3	⁽³⁾	25	16
Ultra SCSI⁽²⁾	20	8	1.5	⁽³⁾	25	8
Ultra SCSI⁽²⁾	20	8	3	-	-	4
Wide Ultra SCSI	40	16	-	⁽³⁾	25	16
Wide Ultra SCSI	40	16	1.5	-	-	8
Wide Ultra SCSI	40	16	3	-	-	4
Ultra2 SCSI^(2,4)	40	8	⁽⁴⁾	12	25	8
Wide Ultra2 SCSI ⁽⁴⁾	80	16	⁽⁴⁾	12	25	16
Ultra3 SCSI or Ultra160 SCSI ⁽⁶⁾	160	16	⁽⁴⁾	12	⁽⁵⁾	16
Ultra320 SCSI ⁽⁶⁾	320	16	⁽⁴⁾	12	⁽⁵⁾	16

Notes:

(1) The listed maximum bus lengths may be exceeded in Point-to-Point and engineered applications.

(2) Use of the word "Narrow", preceding SCSI, Ultra SCSI, or Ultra2 SCSI is optional.

(3) LVD was not defined in the original SCSI standards for this speed. If all devices on the bus support LVD, then 12-meters operation is possible at this speed. However, if any device on the bus is singled-ended only, then the entire bus switches to single-ended mode and the distances in the single-ended column apply.

(4) Single-ended is not defined for speeds beyond Ultra.

(5) HVD (Differential) is not defined for speeds beyond Ultra2.

(6) After Ultra2 all new speeds are wide only.