glennw@dadla-b.UUCP (11/10/83)
I noticed a comment yesterday on incompatabilities (whew!) between
the Hayes Smartmodem and the USR Auto Dial and Password. I am happy to
report that USR has finished a new rom which corrects the following problems:
Problem New Rom
no OK returned after an ATZ reset command - OK now returned
powerup default to non-echo of commands - echos at powerup
unrecognized commands halt processing of command line -
unrecognized commands now ignored and rest of line processed
Also, a recent article in PC World reviewing modems registered a complaint
that the USR modem would drop the line and answer an incoming call while
in the middle of a call. The writer exposed a common ignorance of the
telephone system - the only way such a thing can happen is if you have a
function such as call waiting on your line, which beeps when another call
is coming in. Otherwise, neither a person or modem can possibly know that
another caller is trying to get in. Modems are basically incompatible with
such a function, because it is GUARANTEED to cause garbage characters and
likely to interfere sufficiently with the carrier to cause one of the modems
to time out and drop the line. Modems constantly monitor the carrier, and if
the carrier signal-to-noise ratio drops too low (no carrier detect) for longer
than a certain period, the modem hangs up. This timeout can be from 200 mS to
1 second. The USR modem presently uses a 200mS timeout, but they may change
it to more like 1 second to reduce the chance of dropping the line.
The new rom is presently only available in an EPROM version at a $20
surcharge, but it will likely be rommed (sp?) soon and available as a
standard option. The more people ask for it, the faster it will be available..
Speaking of options, if you are interested in the Password,
be aware of the no charge male/female connector option; if you don't
specify, no telling what you will get!
Glenn Widener
Widener Consulting
270 SE 15th #5
Hillsboro, OR 97123
(503) 648-0363