21 Jan
2023
21 Jan
'23
3:58 a.m.
Paul Berger via cctalk wrote:
Indeed not not all SCSI terminators are created equal, there where three
types of signalling used Single Ended (SE) High Voltage Differential
(HVD) and Low Voltage Differential (LVD). LVD was created to squeeze a
bit more speed out of parallel SCSI.
That's not exactly correct. The reason for differential signalling was to be
able to use longer cables for a given speed. As speeds increased, the
useable length of an SE SCSI cable became prohibitively short and LVD
was devised to overcome this in a way that was relatively compatible with SE.
Also, just like what is now known as World War I was originally the Great War,
what we now known as HVD was originally known as just "differential SCSI".
Older equipment which is labelled "differential" is likely to be what we
now call HVD and connecting it to older SE only equipment may not work out well.
Regards,
Peter Coghlan.