Verbose modems (Re: MORE 6386 UUCP WOES)

Michael "Ford" Ditto ditto at cbmvax.UUCP
Thu Nov 10 18:53:18 AEST 1988


In article <6916 at chinet.chi.il.us> les at chinet.chi.il.us (Leslie Mikesell) writes:
>Where is the EIA signal to indicate 9600 vs. 4800 vs. 2400 vs. 1200
>baud connection?  Where is the software support for it?

All gettys have some kind of autobaud support, and don't require anything
nonstandard from the modem.

>  The real
>point is that modern microprocessor controlled modems have many more
>features than those available when the EIA signals were defined (although
>it is still reasonable to expect DCD to indicate a connection to a
>remote modem).  ASCII strings are the only way to access the new features,

Why do you think this?  I have my doubts about using a new feature that
was added in a way that does not work with commonly used software.  I
think that the more sophisticated modems get, the dumber they should look
to the computer; fixed bit rate, completely transparent flow control, etc.
All these things should be configurable, but they don't need to change "on
the fly".  If the modem is so smart, let IT worry about the details and
just present a boring, old byte-stream to the computer, very much like a
socket ... there are "connect" and "disconnect" concepts (CD/DTR), but
that's about the only thing that the modem and computer need to
communicate to each other aside from the "bytes".

>  Why doesn't uucp's dialer pay attention to the CONNECT message and
>change speeds if necessary?

When would it be necessary to change speeds when dialing?  Why should
a modem accept dialing commands at one speed and then suddenly start
speaking another speed?  Yes, I know there are modems that do this,
but that doesn't mean it's a good idea.  There are also very
sophisticated modems that hide all the details of the connection and
don't require any communication other than the common EIA signals.

Dialing control, of course, is another story entirely...
-- 
					-=] Ford [=-

"The number of Unix installations	(In Real Life:  Mike Ditto)
has grown to 10, with more expected."	ford at kenobi.cts.com
- The Unix Programmer's Manual,		...!sdcsvax!crash!elgar!ford
  2nd Edition, June, 1972.		ditto at cbmvax.commodore.com



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