chris%umcp-cs%csnet-relay@sri-unix.UUCP (11/19/83)
From: Chris Torek <chris%umcp-cs@csnet-relay> The solution we made up for doing real carrier detect in the DZ and DH drivers, while still letting one open the line for dialing, was to add extra flags to force an assumed carrier until a real one is detected, and then when the real one goes away go ahead and drop the line. Avoids the "can't open dialer 'cause there's no carrier; can't get carrier without dialing" catch-22 and still hangs up on loss of carrier. This was done for a special major device number, and has the extra feature of letting us use the same lines for dialing in & out (trying to use one going out when it's already got open gives a ``mount device busy'' error). Chris