-----Original Message-----
From: cctalk [mailto:cctalk-boun...@classiccmp.org] On Behalf Of Grant Taylor
via cctalk
Sent: Wednesday, June 05, 2019 10:42 AM
To: cctalk@classiccmp.org
Subject: Re: Modems and external dialers.
On 6/4/19 8:30 PM, allison via cctalk wrote:
> Keep in mins the hardware for auto dial required some for of micro and
> that was a post 1974 thing for the most part.
Why did it require a micro? Could the host not perform the function
that the micro would do?
> A few before that had a lot of TTL state machine to do that.
> They obviously weren't cheap.
Why did that state machine need to be implemented in electronics?
Why couldn't that state machine be implemented in software on the host
using the modem & auto-dialer?
> The dialer was often not at all as it was the human that dialed the phone.
~chuckle~
> I know of none that did both functions that required a second serial port.
Okay.
Reading the links that Ethan provided, it sounds like some auto-dialers
did use a second port, but it was not a second (recommended) standard
232 port. Instead it was an RS-232 and RS-366.
Aside: RS-366 sounds odd. A combination of serial signaling and
parallel signaling on the same port. But not the same as a traditional
parallel printer port.
> My first modem was a box about 12x8x2.5 inches and it was an all analog
> modem good for 110/300 baud and it required connection to the phone line
> (pre-modular connector) and you dialed the various (and relatively scarce)
> BBSs and when you heard the tone hit the switch that put the modem on
> the phone line and you would see the carrier and data lamps do their
> thing. That was 1978ish.
Aside: I assume that you're talking about before the small 6-position 2
or 4 conductor plugs. Or are you referring to the older than that
not-quite-square 4 pin plug? Or was the modem actually hard wired in
with no plug / jack at all?
> A modem that could dial was maybe 1983-5 or so at affordable prices
> (under 300$) for 300 baud.
*nod*
I have this mental picture, which I think is based on something I've
seen at some point in the past, that was a device that attached /
actuated / ??? a traditional rotary dial phone. As in it had a finger
that interfaced with the dial and something that could rotate it to dial
the digit in question, rewind (term?), and dial the next digit in question.
--
Grant. . . .
unix || die
I used to have Rixon 212A autodialers. There were about the size of a Hayes
modem, and only had 1 RS232 port and a phone jack on the back. I no longer have
the modems, but I do still have one owner's manual in a binder. IIRC, the
dialing was done through a software interface.
The other dialers mentioned before were probably twice the size of the Rixon.
I do still have one 300 baud acoustical modem in stock, if anyone is
interested. AC adapter is included.
Cindy
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