telecom@ucbvax.ARPA (06/26/85)
From: Moderator <Telecom-REQUEST@MIT-XX.ARPA> TELECOM Digest Tuesday, June 25, 1985 7:57PM Volume 4, Issue 205 Today's Topics: Penril woes Ven-Tel Modem schematics needed Phone dialers and modems single line dial in/out on Altos Re: TELECOM Digest V4 #202 Clicks and Handsets ---------------------------------------------------------------------- Date: Friday, 21 June 1985 07:33-MDT From: Steven Taylor <decvax!mcnc!ecsvax!taylor@Ucb-Vax.ARPA> Subject: Penril woes There are at least 3 prom sets for the Penril autodialers in question. The "vanilla" prom set does indeed keep cd high (as best I remember) in order to keep terminals happy. (It was designed to be used with dumb crt's as an outgoing device.) A second version was designed specifically to work with Develcon dataswitches in a bidirectional mode. That is, they could be used on the switch for outgoing calls or incoming calls on the same port. I KNOW that this prom set does not keep cd high, but brings it up in response to DTR coming high. (Remember, the dataswitch does not bring dtr high until it is trying to initiate a call. This difference may be the root of the problem mentioned.) If you need more detailed info on this, I'll be glad to discuss this firmware in detail. Finally, there is also, I understand, a "Hayes compatible" firmware set available now as well. Your Penril rep should be willing to work with you on getting a prom that will work, but you may have to get hin to do some investigation before he will admit that the three version (minimum) really exist. Steven Taylor Distributed Networking Associates Charlottesville, VA 22901 (804) 979-0656 ------------------------------ Date: Saturday, 22 June 1985 22:00-MDT From: John Ruschmeyer <vax135!petsd!moncol!john@Ucb-Vax.ARPA> Subject: Ven-Tel Modem schematics needed Monmouth College is in need of the schematics (or any other technical information) for the Ven-Tel MD 212 PLUS modem (specifically, one of the older models in the black case). Recent lightning strikes have disabled two such modems. Ven-Tel's only suggestion is to send the modems to them for service. Based on a previous dealing with them, however, the repair would cost more than replacement. Any pointers to a schematic, therefore, will be appreciated. Thanks in advance..... -- Name: John Ruschmeyer US Mail: Monmouth College, W. Long Branch, NJ 07764 Phone: (201) 222-6600 x366 UUCP: ...!vax135!petsd!moncol!john ...!princeton!moncol!john ...!pesnta!moncol!john ------------------------------ Date: Monday, 24 June 1985 17:05-MDT From: sasaki@harvard.ARPA (Marty Sasaki) Subject: Phone dialers and modems I have this cheapie phone that has a last-number-redial button. I connect the phone to my modem, and the modem to the telephone line. Everything is fine when I'm using my phone normally. The fun comes in when I push the "data" button on the modem. This seems to disconnect the phone from the line. Unfortunately, the memory for the last-number- redial seems to need power; it forgets when I push the "data" button. I've been thinking of getting a better phone (one of Panasonic's "Easa-phones") that has a bunch of remembered numbers, and was wondering whether I would have the same problem of forgetting numbers? Is there some way around this? I used to have the phone and the modem in parallel and would sometimes have problems with noise, especially when I hung up the phone. ---------------- Marty Sasaki net: sasaki@harvard.{arpa,uucp} Havard University Science Center phone: 617-495-1270 One Oxford Street Cambridge, MA 02138 ------------------------------ Date: Saturday, 22 June 1985 20:02-MDT From: Randy Suess <ihnp4!wlcrjs!randy@Ucb-Vax.ARPA> Subject: single line dial in/out on Altos For all you Altos 586 owners out there that have been stymied by your lack of ability to use a single modem/port for dial in and dial out, be unhappy no more. I have finally got it going using the new ARK 2400 baud modem. The problem has always been that the Altos requires cd (pin 8) to be always hi for dial out, but to only be hi on carrier detect for dial in. On a DCHayes, for instance, you had to have the switch 6 up for dial in and down for dial out. The ARK modem uses a "intelligent" cd pin. There is a wiring change to be done on the cable. Pin 6 on the Altos goes to pin pin 5 on the modem. You then of course have to modify the various programs used with the line. I use it on my system for uucp dial out and in. I just replaced /usr/lib/uucico with a shell script that tests for usage, disables the port, then calls a renamed uucico. After uucico finishes, it re-enables the port for dial in. I have been receiving news and polling other sites with it with no problems. The ARK's are the best 2400 baud modem going for the price. They have built in mnp protocol, and list for $595. Hope this has been of some help. -- .. that's the biz, sweetheart .. Randy Suess Chi-Net - Public Access UN*X (312) 545 7535 (h) (312) 283 0559 (system) {ihnp4|ihldt}!wlcrjs!randy ------------------------------ From: ihnp4!ihopa!riccb!jmc@Berkeley Date: 25 Jun 85 08:12:49 CDT (Tue) Subject: Re: TELECOM Digest V4 #202 Clicks and Handsets In regards to hearing your voice back in your ear via the phone line, in a 2W circuit this is called TRANSHYBRID LOSS (or lack of it as it were), in a 4W circuit this is called SIDETONE. It was orginally there as a function of the 2W to 4W hybrid circuit on a two wire line. People now associate this with the phone working. If a 4 wire line terminates in a handset or headset then a certain portion of voice is bleed back to the ear intentionally. Jeff McQuinn just VAXing around ------------------------------ End of TELECOM Digest *********************