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Re: History AT&T early modem developments? [telecom]

***** Moderator's Note *****

> Perhaps you can confirm something: an old AT&T tech told me that > before N carrier was introduced, toll cables were so precious that it > was common to use duplex/simplex repeating coils to make Ghost > circuits from phantom circuits, and to obtain "Wraith" circuits from > Ghosts. He told me the Wraiths carried telegraph traffic, sometimes > working against ground and sometimes via other Wraith circuits, and > that testmen had to know American Morse code because the testboards > used Morse sounders and keys for communications between offices. True?

I don't know all the technical details but basically the above sounds correct. Before carrier toll circuits were rare.

There are two excellent books I strongly recommend which go into detail about this stuff (and where my questions arise from): They are:

"A History of engineering and science in the Bell System" / prepared by members of the technical staff, Bell Telephone Laboratories

vol 1. The early years (1875-1925) vol 3. Switching technology (1925-1975)

Vol 1 covers the early toll circuits, instruments, and switching up to panel and would answer the questions above. Vol 3 covers later switching--#1, #4, #5 crossbar and ESS.

(Vol 2 covers military products).

I also recommend two books on IBM technical history: "IBM's Early Computers" by Bashe et al and "IBM's System/360 and System/370" by Pugh et al.

I will note all the books are technical/research histories and tend not to cover manufacturing, marketing, or financial issues.

Reply to
hancock4
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[snip]

Amazon has the switching book for about $30, but there's a "Transmission Technology" volume that starts at $65.00. Do you have that one? Is it worth it?

[snip]

Bill

Reply to
Bill Horne

Sorry to bother the group, but I'm trying to send private email to snipped-for-privacy@bbs.cpcn.com on this topic and it is not going through. So please contact me with an email address that works.

jhhaynes (at) earthlink (dot) net

Reply to
Jim Haynes

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