12 Apr
2001
12 Apr
'01
8:15 a.m.
On Wed, 11 Apr 2001, Tony Duell wrote:
IIRC, the RS232 standard specifies a 25 pin connector.
So strictly there
are no 9 pin RS232 ports. If you mean why do PC/AT machines have a DE9P
for the serial port, it was because (a) 9 pins is enough for the active
signals on said port and (b) you can fit a DE and a DB on a single PC
bracket, so you could have a combined parallel/serial adapter card. Which
IBM introduced with the PC/AT IIRC.
Oh, but then you lose a lot of fun. The Amiga DB25 serial port features
among others audio output on some pins. =)
And Apple used the 8 pin mini-DIN on the Mac+ and
later because there
wasn't room for the DE9 connector used on the earler Macs. Hardware
hackers have been complaining ever since -- those mini-DINs are about the
worst connectors in the world to wire!
Try a DIN-13 for size.