DB-9 is the PC
serial connector;
That's RIGHT! The original (5150) PC used a 25 pin connector
(DB25), but
not all of the signals were always used.
Therefore, a DB25 that implements 1-8 and 20 would be a DB9!
What about a DB shell connector that implements 2-8, 20, 22 (those are
the pins copied on the DE9 PC/AT serial port IIRC) ;-)...
Semi-seriously, I have plenty of serial cables that do only have pins 1-8
and 20 fitted. Quite a common arrangement. And yes, I have been known to
call them DB9s as a joke. Problem is, if I ask for that down the local PC
shoop, I'll get a cable with a DE9 connector on the end.
-tony