revc@gwsd.UUCP (Bob Van Cleef) (05/25/85)
There is a problem using the Hayes modems as an ACU. To originate calls (outgoing) you must disable the carrier detect (switch 6). To receive calls (incoming) you must enable carrier detect. Has anyone figured out a way to allow you to use a Hayes modem on a uucp bi-directional line? Bob
george@mnetor.UUCP (George Hart) (05/30/85)
> There is a problem using the Hayes modems as an ACU. > > To originate calls (outgoing) you must disable the carrier detect (switch 6). > To receive calls (incoming) you must enable carrier detect. > > Has anyone figured out a way to allow you to use a Hayes modem on a uucp > bi-directional line? > > Bob Yes. Get another modem such as the POPCOM X100 which is a Hayes superset and controls all the switch positions in software. It can be used in a totally Hayes-compatible mode or in it's own superset mode. -- Regards, George Hart, Computer X Canada Ltd. {cbosgd, decvax, harpo, ihnp4}!utcs!mnetor!george
merlyn@avalon.UUCP (Steve Humphrey) (05/30/85)
> There is a problem using the Hayes modems as an ACU. > > To originate calls (outgoing) you must disable the carrier detect (switch 6). > To receive calls (incoming) you must enable carrier detect. > > Has anyone figured out a way to allow you to use a Hayes modem on a uucp > bi-directional line? > > Bob No, it is not possible with the standard software to use the Hayes modem bidirectional. Reason: The cu/uucp software accesses a modem in a way that requires DCD to be up. The 3B2 is capable of allowing access with DCD down, and I've modified the cu/uucp software to do that. Even running that modified software, though, I still had minor problems with the modem, thus I don't use it any more. (I never identified the problems, so I don't know who to blame.) I sent my software modification to DAN (as in Honey-DanBer UUCP) so it may appear in a later release. If you find it expensive to (1) toss out a pile of Hayes modems and buy other modems (e.g. Ventel, Penril, AT&T 2224C all work fine), (2) use two ports on the 3B2 (one incoming, one outgoing), or (3) buy the source so you can do the software fix, then consider a hardware work-around: The Hayes keeps the CTS (Clear To Send) signal up while connected to the 3B2. The work-around is to build a small circuit that uses CTS and DCD from the modem to build a pseudo-DCD signal for the 3B2. The trick is to keep the pseudo-DCD signal up while the CTS signal is up, regardless of the state of the DCD signal, EXCEPT when the DCD goes from high to low (i.e. when a connection to a remote machine is dropped). At that transition, the circuit drops the pseudo-DCD for a short interval (about one second should be enough) then raises it again. This tells the cu/uucp software that the connection dropped, so the software quits; raising the pseudo-DCD back up again lets another outgoing call be placed. What does the circuit look like? I wish I knew, sorry. We were starting to design the circuit, since we have a closet full of Hayes modems that we'd like to use, but other work took precedence. Interested parties can drop me a note and I'll give you what info I have, but be warned: I'm not a hardware jock so I don't know much more than I've described above. Steve Humphrey ...!avalon!merlyn AT&T -- Steve Humphrey hogpc!merlyn or lz3f310!merlyn