Hayes Smartmodem 2400 dialin problems

[Royal Ontario Museum]

We have been using modems on Xenix for a long time with much success.
It comes as a surprise that we are having so much trouble now.

Configuration:

	Dell 386, SCO Xenix V 386 2.3.

The symptoms are as follows:

	The modem works perfectly for a single call.
	On the second call, it answers and connects at 1200.
	For some reason, after the first call the modem has dropped
	its host connection to 1200.  It looks like Xenix is still
	trying to connect at 2400, though I cannot be sure.
	Sometimes it will not answer at all.
	No amount of enabling/disabling will fix the line.
	Only a hardware reset of the modem and sometimes a system
        reboot will fix the line.
	The modem behaves exactly the same on a Computone Cluster
	controller port and on a 'native' com1 port.

	ATI 2400 baud modems with MNP5 exhibit similar behavior.
	We can sometimes get a connection through the ATI modem by
	setting the baud rate cycle to start at 4800 instead of 2400.

What is most bothersome is that we formerly had an early model Hayes
Smartmodem 2400 running with exactly the same setup as the new one
running for 1.5 years with no problems.  In fact, it is still running
perfectly on an identical hardware/software configuration.

Did Hayes change something in their modems to make them not work?  Did
the clone modem manufacturers clone the change?

We are experiencing the same problem on another system, so I do not
think Dell hardware is part of the problem.
Mark T. Dornfeld
Royal Ontario Museum
100 Queens Park
Toronto, Ontario, CANADA
M5S 2C6

mark at utgpu!rom      - or -     romwa at utgpu