Modems and external dialers.

[Grant Taylor]

On 6/5/19 11:38 AM, Fred Cisin via cctalk wrote:
> 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.

That sounds suspiciously like you've seen something like I was trying to 
describe.

> 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.

I've seen something conceptually similar within the last 10 years to 
take a handset off hook in support of a wireless headset.

> Carterfone was extremely significant as it allowed connecting to the 
> phone line "if it did not damage or interfere with normal operations".

ACK

> 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 

I can't say as I'm surprised.

> 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.

ACK



-- 
Grant. . . .
unix || die