telecom@ucbvax.ARPA (02/19/85)
From: Jon Solomon (the Moderator) <Telecom-Request@BBNCCA>
TELECOM Digest Mon, 18 Feb 85 19:08:56 EST Volume 4 : Issue 161
Today's Topics:
Telebyte 'Accelerator' Data Compression Box
Bell 212AR - Revisited
Phone Noise
Re: TELECOM Digest V4 #155 - phone noise
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Date: 17 Feb 1985 14:52:39 PST
Subject: Telebyte 'Accelerator' Data Compression Box
From: Eliot Moore <SWG.ELMO@USC-ISIB.ARPA>
To: telecom@MIT-MC.ARPA
Catching up on my paper mail this weekend I noticed an ad for Telebyte
Corp's "Accelerator", claiming >3:1 compression rates, error free.
The usual questions: Are these guys for real? Has anyone used one?
Are they shipping? What's the going price?
Elmo
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Date: 18 Feb 85 09:10:18 PST (Monday)
From: Cottriel.ES@XEROX.ARPA
Subject: Bell 212AR - Revisited
To: STEVEH@MIT-MC.ARPA
Steve:
AR is just a version designation. Don't worry about it.
Assuming that a connection is in progress, drop DTR (Data Terminal Ready)
at pin 20 of the EIA interface. The modem will go on hook when DTR is not
true (i.e. negative voltage).
However, you will have to bring it back up again in order for the next
call to be answered. A few milliseconds is all that is required, but to
make sure, ya outta drop it for a couple seconds, then bring it back up.
(To be polite, ya probably outta send a message: "Connection Timed Out"
or something equally mundane, just prior to dropping DTR).
-----
Hints/Suggestions - not relevant to the above discussion:
Another way to implement operation is to detect Ring Indication (Pin 22),
then turn on DTR. At the ~next~ ring the dataset will answer.
When you want to indicate that the computer is unavailable,
bring up pin 25 (Busy).
John
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Date: Monday, 18 Feb 1985 11:01:13-PST
From: libman%grok.DEC@decwrl.ARPA (Sandy Libman)
To: telecom@bbncca.ARPA
Subject: Phone Noise
>Date: Sun, 10 Feb 85 16:54:54 EST
>From: Ron Natalie <ron@BRL-TGR.ARPA>
>To: fortune!redwood!rpw3@ucb-vax.ARPA
>Subject: Re: TELECOM Digest V4 #155 - phone noise
>Of course the problme with the radio station on the modem could be
>some poor design inside the modem, causing the modem to become a
>poor AM receiver. I used to have the same problem with my stereo
>when I lived two blocks from an AM radio station.
In my case the Bell 212A also received the radio station, but wasn't
bothered by it. The DF03 was useless until the Radio Suppressor was
installed. I made the assumption that the 212A had that filter built in.
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End of TELECOM Digest
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