5 Jun
2019
5 Jun
'19
9:01 a.m.
-----Original Message-----
From: cctalk [mailto:cctalk-bounces at classiccmp.org] On Behalf Of Grant Taylor via
cctalk
Sent: Wednesday, June 05, 2019 10:42 AM
To: cctalk at 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
---
This email has been checked for viruses by Avast antivirus software.
https://www.avast.com/antivirus