02-03-2018, 06:28 AM
I'll give the DTR hangup mode a try. I did cut and re-solder the jumpers to use DTR/DSR as described in the instructions. And I cut the jumper at the red arrow to remove the DTR-DSR bridge. AT&D[#] is not described in the manual so I never bothered to test that feature. Thanks for the update.
I'm not concerned about RTS/CTS because I (and most others in the retro-computing world) operate at relatively slow speeds of 9600 baud and less so software flow control is the most we'd use.
If you look on page 1-21 of the Hayes reference it describes the DSR features and various behaviours. The DSR options are logic-tied to AT&Q options which are also logic-tied to AT&D DTR options on page 1-18.
The problem with tying CD to the DSR pin is that CD is always low without a remote connection so the computer thinks the modem isn't ready and won't communicate while offline.
DSR on the other hand goes high in local mode when DTR is sent by the host computer, stays high during the remote connection, goes low on a remote disconnect, and then comes back high when the host computer cycles DTR off and back on.
At least this is my understanding of DSR use with respect to BBS operation.
I'm not concerned about RTS/CTS because I (and most others in the retro-computing world) operate at relatively slow speeds of 9600 baud and less so software flow control is the most we'd use.
If you look on page 1-21 of the Hayes reference it describes the DSR features and various behaviours. The DSR options are logic-tied to AT&Q options which are also logic-tied to AT&D DTR options on page 1-18.
The problem with tying CD to the DSR pin is that CD is always low without a remote connection so the computer thinks the modem isn't ready and won't communicate while offline.
DSR on the other hand goes high in local mode when DTR is sent by the host computer, stays high during the remote connection, goes low on a remote disconnect, and then comes back high when the host computer cycles DTR off and back on.
At least this is my understanding of DSR use with respect to BBS operation.