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.

RE