[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index]

Re: Super Serial Card Question?

David Wilson wrote:

Michael J. Mahon wrote:


I suspect the IBM PC designers would have followed the same convention
except that they reused the DB-25 for both the serial and the parallel
ports, making a gender shift in one desirable from a human engineering
point of view.

One could argue that they should have decided to make the parallel port
male, since female serial connectors (on boxes) were widespread by the
time the PC was designed.



The choice the IBM PC designers made (male RS-232 sockets) is actually
the correct one.

The RS-232 standard states that DTEs (Data Terminal Equipment) will be
associated with the male connector while DCEs (Data Communication
Equipment eg modems) will be associated with the female connector.


Thanks for the correction, David.

I specifically looked up RS-232 connectors before answering to get
that information, and read that it was not originally part of the
standard, and the _de facto_ convention had developed to use male-male
cables...  Ah, well--not everything on the Internet is true...  ;-)

-michael

Music synthesis for 8-bit Apple II's!
Home page:  http://members.aol.com/MJMahon/

"The wastebasket is our most important design
tool--and it is seriously underused."