Anyone know anything about old TEC Terminals?
hilpert at cs.ubc.ca
Mon Jun 4 16:31:44 CDT 2007
Mr Ian Primus wrote:
> > Well if you are wiring up your new TERMINAL and you
> > have the standard
> > in front of you with a page that says data TERMINAL
> > equipment then
> > you'd have to be pretty bloody minded to be
> > different :-)
> > Having said that, someone must have done it just to
> > be contrary :-)
> Well, they never could decide on what gender to make
> the connectors on the back of the terminal...
Indeed, I couldn't say whether I ever saw a terminal that was actually
*electrically* wired as DCE, but there was no shortage of terminals and
other equipment that got the gender wrong.
I don't have the RS232 spec in front of me but I have always been of the
understanding that it explicitly specifies that DCE shall be a female
connector and DTE male. You should be able to simply look at the
gender of the connector and know whether it was DCE or DTE. You would also be
able to look at a cable and know (in part) what it did: a M-F cable would be
straight thru, a F-F cable would be a null modem.
It has always been a source of annoyance (to me) with such equipment that you
can't rely on this and have to check everything.
(Either that or somebody correct me about the spec.!)
I actually just received an old (70s) RS232 breakout box. Rather than having a
male and a female DB25 which would make it trivial to insert in a line, it has
two female DB25s, which not only violates the spec but pretty much guarantees
that you're going to have to monkey around with an additional gender-changing
cable whenever you use it!
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