- HP50 (Half Pitch 50) Male to HP68 (Half Pitch 68) Male
Half Pitch 50 Male (Micro DB50 Male) - Used for scsi-2 applications: scanner, removable storage drive, controller, external
cdr/cdrw. The Micro DB50 connector has 50-pins arranged in two rows one on top of
the other. The top row has 25 pins and the lower row has 25 pins. Most 8-bit SCSI FAST
(up to 10 Mbytes/sec) computers and host adapters use this 50-pin High-Density connector.
Commonly used on Apples and Mac, and some older Sun 8-bit workstations. This connector is seen increased use on Scanners
and Iomega Zip Drives.
HP68 Male - Probably the most common SCSI connector used today. Used on all SCSI Wide applications and some old DEC single-ended SCSI
this connector provides a highly secure connection. Used for scsi-3 applications: scanner, removable
storage drive, controller, external cdr/cdrw, ultra/2. The HP68 connector has
68-pins arranged in two rows one on top of the other. The top row has 34 pins and
the lower row has 34 pins.
- SCSI 2 to SCSI 3
- SCSI 2 - This standard was introduced in 1989 and gave rise to the Fast SCSI and Wide SCSI variants.
Fast SCSI doubled the maximum transfer rate to 10 MB/s and Wide SCSI doubled the bus width
to 16 bits on top of that (to reach 20 MB/s). However, these improvements came at the
minor cost of a reduced maximum cable length to 3 meters. SCSI-2 also specified a 32-bit
version of Wide SCSI, which used 2 16-bit cables per bus; this was largely ignored by SCSI
device makers because it was expensive and unnecessary, and was officially retired in
- SCSI 3 - Before Adaptec and later SCSITA codified the terminology, the first parallel SCSI devices
that exceeded the SCSI-2 capabilities were simply designated SCSI-3. These devices, also
known as Ultra SCSI and fast-20 SCSI, were introduced in 1992. The bus speed doubled again
to 20 MB/s for narrow (8 bit) systems and 40 MB/s for wide. The maximum cable length
stayed at 3 meters but ultra SCSI developed an undeserved reputation for extreme sensitivity
to cable length and condition (faulty cables, connectors or terminators were often to
blame for instability problems).