Tip and loss of carrier

[scw%ucla-locus at cepu.UUCP]

From:  Steve Woods <cepu!scw at ucla-locus>


	It doesn't appear that tip (dh driver?) detects loss of carrier
	on the dialout port.  Is that a feature or have i not said the proper
	incantations?

Many modems on dialout lines hold carrier detect high, or else your dh
driver is hacked to ignore CD. The reason for this is that if the
driver expects CD it won't let you send the dial commands until it sees
CD, but it'll never see CD unless you can send the Dial commands
(famous Catch 22).  Also (at least in the Vanilla V7) the KL (DL-11E)
driver looks at CTS (but calls it CD). Most drivers *DON'T* seem to
really look at CD but rather at CTS, because most Serial lines aren't
connected to Modems but rather are connected (in)directly to terminals.