On Wed, Dec 26, 2018 at 10:21:56PM +0000, jim bell wrote:
>>  In the late 1970's, there was a technology in development called "ISDN",  https://en.wikipedia.org/wiki/Integrated_Services_Digital_Network  (Although, you wouldn't know this from this WIkipedia article, which merely makes reference to a 1988 standard.)    During the 1970's, I was reading the magazines Electronics, and EDN (Electronics Design News), and others, and there were articles and ads for ISDN chips.  Keep in mind that during the 1970's, commonly-available modems worked at speeds of 300 bits/second and 1200 bits/second.  If ISDN had actually been delivered promptly, it would have leapfrogged the 9600, 14.4kbps, 28.8 kbps, and higher speeds.  However, ISDN was probably developed on the Phone Companys' calendar, very slowly, while the rest of electronics (including modems) were operating on a much-faster time frame.
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>> The ISDN idea was that a telephone line would have quantity 2, 64 kilobits/second channels, as well as a 16 kilobit/second channel.  
>> However, one additional good reason that ISDN didn't succeed was simple:  The phone companies would certainly have charged a high per-month fee for ISDN lin es.  (And such a service would have had a box, analogous to a 'modem', into which your computer would have connected.)  The eventual alternative, buying the modems which eventually appeared on the market, was comparatively free.  I think there was a time in the late 1970's when phone companies expressed resentment that their users were employing modems on their phone lines.  
>  >                   Jim Bell


>The phone companies not only expressed resentment, it was in fact
>"illegal" to connect anything not made/sold by Bell directly to the
>phone system. This is at least part of the reason that early modems
>were "acoustic couplers" (like the modem used in the movie WarGames).

 Something just now occurred to me!  In that movie, WarGames, the technique later called "wardialling" was used, dialling up sequential phone numbers to identify modems.   But, the modem in that movie was shown to be an acoustic-coupled one.  I don't know if acoustic-couplers were capable of dialling, automatically.  They shouldn't have been, unless somebody added a circuit which allowed quick connects and disconnects to be made, probably using some kind of mechanical relay.

However, by 1983 (the year of that movie) connecting to telephone lines was legal.  See the Carterphone decision.

                         Jim Bell