Let's not get into an argument on this... The latest spec is RS-232F,
I believe. It now contains definitions for the DB25 and RJ-45
connectors and maybe a few others. At over $100 for the spec, I don't
have a strong desire to find out what else. Amazingly, it does not
contain definitions for the commonly-used DE9 connector.
In D-shell connectors, the second letter specifies the size of the
connector shell. There are many pinouts and arrangements used in B-
sized shells, including Sun's video connections. The 15 pin connector
uses an A shell, while the 9 an E shell. Now that we note this, I
seriously doubt that we have any chance of convincing the world to
use the correct nomenclature, are we...
And lastly, the Macintosh has never used RS-232 levels on its serial
ports. Instead, they (we for a while) used RS422 levels, centered
around zero volts. This allowed the creation of AppleTalk and its
predecessor, AppleBus. It also allowed interfacing to the outside
world and the commonly used RS-232 levels. All have now been phased
out and Apple uses Ethernet and USB on its systems.
OK, so now back to our regularly scheduled radio
discussions... ;-) :-) :-)
On Nov 22, 2005, at 6:28 PM, Don Wilhelm wrote:
Just a tid-bit of information here (useless though it may be) - the
RS232
standard does specify a connector - and in fact it is the DB-25
connector.
Other connector configurations may carry the RS-232 signal levels and
signalling protocol, and can come in many different flavors. The
one we
seem to be most concerned with is the DB-9 (more properly a DE-9)
connector
which has become the de-facto 'standard' on IBM compatible PCs.
The Apple
world has used mini-din connectors for most everything (including
RS-232
level signals) for a long time.
73,
Don W3FPR
-----Original Message-----
Actually RS-232 refers to the signal names and levels, although a
DE-9 (Cannon nomenclature) connector is often used (sometimes it is a
DB-25, particularly for modems).
A good place to find information related to Macintosh radio
applications is the "ham-mac" mailing list <http://mailman.qth.net/
mailman/listinfo/ham-mac>.
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