On Wed, 5 Jun 2019, Grant Taylor via cctalk wrote:
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.
Typically a thick flat disk that clipped to the dial, with a motor and a
clutch to permit the dial and disk to return to rest position.
But, a FINGER is such a better visual image!
Prior to Carterfone V Western Electric, (1968) . . .
There were DAAs RENTED by TPC ("The Phone Company" (cf, "The President's
Analyst")), dialers RENTED by TPC, and acoustic couplers in the
after-market.
There were devices that sat on top of the "hook" of the phone (where the
handset rested to hang up, with the handset on top of them. A solenoid
could lift the handset for "off-hook", and set it down again for hang-up.
In some cases, such as answering machines, that sandwich in between the
phone and handset had speaker and microphone, but I don't recall ever
seeing a modem made that way - "common sense" held that you needed "cups"
for the handset for noise isolation.
Carterfone was extremely significant as it allowed connecting to the phone
line "if it did not damage or interfere with normal operations".
Carter started trying to peddle his systems in 1959, but AT&T
So, Carterfone is to thank for all direct connect telephone devices,
indeed, all "foreign attachments", even a plastic cup that clipped on the
phone handset for a little more privacy!
AT&T rejected ANYTHING that connected, on the grounds that even that
plastic privacy cup degraded the quality of the sound.
http://www.historyofcomputercommunications.info/Book/1/1.2CarterfoneATT_FCC48-67.html
Prior to Carterfone, you had acoustic couplers, switch-hook solenoids,
DAAs RENTED by TPC, and only TPC dialers. Once direct connection was
available, you got things like the PhoneMate dialer, and moving piece of
mylar with marks and photocells.
Later, "Touch tone" made it possible to "dial" by making noises into the
phone, both simple dialers (cf. Hayes "ATDT") and simple devices to
implement the full set of DTMF tones (cf. blue boxes, and DTMF C-tone to
turn off FBI phone recording taps)
"Hayes Compatible" was a marketing term to describe anything that used the
same (orsimilar) commands as Hayes. But, Hayes, themselves, never fully
created a standard. Joe Campbell ("C Programmers Guide To Serial
Communications", "The RS232 Solution", etc.) once consulted for Hayes to
try to help them make such a standard out of the myriad devices they
already had extant.
--
Grumpy Ol' Fred ci...@xenosoft.com
