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Richard Erlacher
03/17/06 09:33
Read: 710 times
Denver, Co

#112402 - minor but annoying ...
Responding to: Jon Ledbetter's previous message
I note, from your schematic, that you refer to the 9-pin "d-subminiature" connector, on which the level-shifted signals appear, as a DB-9. It's NOT a DB-anything. the D is the shape, the B is for a shell size not in use in this case, and the 9 is the pin count. The shell commonly used for "RS-232" (used "loosely" in this context) signaling, is an E shell. The one that was used on the "original" PC's FDC is a C shell and the one commonly used for joysticks, MIDI, etc, on the classic sound board, is an A shell. The one used by DEC and SUN, among others, for SCSI connections, is a D shell, and the one commonly used for the PC parallel port is the B shell. The suffix, S or P, is for socket or plug, which should be obvious enough, though it's arguable as well, since it refers to the pins and not the gender of the shell. <sigh> Will it ever end?

Now, I'm not unwilling to use other terminology, but, this, for some reason, has always annoyed me. I admit, it's not from a particluarly rigorous naming/numbering scheme, since the number of pins doesn't seem to be fixed. The common VGA connector would, under this scheme, be a DE-15, while the one we use as the AUI cable in classic ETHERNET, is a DA-15.

I wish this could be settled, either by standard or by convention. Unfortunately, I can have a conversation on the phone with someone who fully believes he understands me, yet, when we're done, we're not at all on the same page.

There can be confusion as to the gender, and size. Well, there are also those wierd versions that SUN, among others, used for monitor connections, with a number of controls along with three coax cables in their bundle, all housed in a C shell.


List of 46 messages in thread
Feedback needed        Jon Ledbetter      12/12/05 13:29      
   Couple of ideas      Sasha Jevtic      12/12/05 14:24      
   Missing      Andy Neil      12/12/05 15:28      
      the source...      Jan Waclawek      12/12/05 16:10      
         Stupid EIA      Andy Neil      12/13/05 00:52      
      Maybe a Name change?      Jon Ledbetter      12/12/05 22:30      
         minor but annoying ...      Richard Erlacher      03/17/06 09:33      
   USB      Ian Bell      12/12/05 16:06      
      Limited Experience      Jon Ledbetter      12/12/05 22:43      
      known bad USB/serial      Jan Waclawek      12/13/05 01:56      
      FYI - Targus PA088      Jon Ledbetter      12/13/05 09:46      
   thoughts      Jan Waclawek      12/12/05 16:17      
      I am so stupid      Jan Waclawek      12/13/05 02:02      
         Kickstart      Jon Ledbetter      12/13/05 07:36      
   attribution      Steve M. Taylor      12/13/05 03:41      
   The ONE thing I always have to look up a      Erik Malund      12/13/05 08:03      
   Ok - Second revision, but still working,      Jon Ledbetter      12/15/05 14:16      
      Nice      Steve M. Taylor      12/15/05 15:12      
         OK      Jon Ledbetter      12/15/05 15:33      
         MAX202 vs. MAX232A      Jan Waclawek      12/16/05 02:32      
         or the 232A      Erik Malund      12/16/05 06:32      
      Polled; Interrupt      Andy Neil      12/16/05 00:39      
         polled tx      Jon Ledbetter      12/16/05 07:48      
            Assorted small ideas      Sasha Jevtic      12/17/05 00:19      
               Not a good idea      Kai Klaas      12/17/05 06:46      
                  Serial speeds?      Sasha Jevtic      12/17/05 08:41      
                     Enhanced specifications      Kai Klaas      12/18/05 06:38      
                        That's a strange spec      Sasha Jevtic      12/20/05 15:04      
      formal stuff      Jan Waclawek      12/16/05 02:59      
         formal      Jon Ledbetter      12/16/05 08:23      
            who's the intended audience      Jan Waclawek      12/16/05 09:15      
   3rd Revision      Jon Ledbetter      12/27/05 08:47      
      Busy?      Jon Ledbetter      01/03/06 12:23      
         more than a couple of comments...      Jan Waclawek      01/04/06 16:27      
            So.....      Jon Ledbetter      01/05/06 15:01      
               what I like or not...      Jan Waclawek      01/06/06 08:25      
                  comments      Jan Waclawek      02/28/06 05:18      
                     Comments on Comments      Jon Ledbetter      02/28/06 09:37      
                        bah...      Jan Waclawek      02/28/06 11:25      
                           more problems      Jan Waclawek      02/28/06 13:20      
                              RE: Problems      Jon Ledbetter      02/28/06 13:36      
                              Something Strange      Jon Ledbetter      02/28/06 13:57      
                                 Nope....      Jon Ledbetter      02/28/06 14:28      
                                    interrupt      Jan Waclawek      02/28/06 15:30      
   All members will enjoy      Ralph Sack      03/16/06 21:55      
   Intel serial intro app note      Sasha Jevtic      03/28/06 15:16      

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