Bell System History Reference Books - TCI Library

BTL 1975 - Switching Technology Chronology 1925-1975 - extract

paul-f@verizon.net (Paul F) — Fri, 28 Aug 2026 10:25:38 -0700

12 pages. Extracted from: A History of Engineering and Science in the Bell System, Switching Technology (1925-1975), pages 605-616 by Paul Fassbender.

BTL 1961 - Dates in American Telephone Technology

paul-f@verizon.net (Paul F) — Wed, 26 Aug 2026 15:39:53 -0700

148 pages. By Dean Hanscom, Historian, BTL. Covers topics from prehistory through the mid-1950s. From the author's introduction:

This book lists important facts and dates for ready reference. It does not
elaborate and references are given only as sources for the dates indicated: other
and more detailed references may exist. With exceptions, 1956 is the closing date:
later advances must in general be covered in later editions.
The references are (with only a few exceptions) to published articles and books.
All such publications are in Bell Laboratories Library, Historical Collection, or
files. References to original laboratory notebooks and files are not given. Different
authors sometimes quote different dates for the same event; I have tried to establish
facts or a weight of evidence from published sources, but in some cases there
are unresolved differences. In a book of this scope, some errors are inevitable.

Contributed by the Connections Museum.

BTL History 2: National Service 1978

paul-f@verizon.net (Paul F) — Wed, 01 Jun 2022 16:13:27 -0700

768 pages, 80 MB, 500-468, A History of Engineering and Science in the Bell System - National Service in War and Peace (1925-1975). Missing pages 24, 25 and 504. Contributed by Sam Etler. Processed by Paul Fassbender

BTL History 5: Communication Sciences 1985

paul-f@verizon.net (Paul F) — Wed, 01 Jun 2022 16:07:31 -0700

541 pages, 44 MB, 500-471, A History of Engineering and Science in the Bell System - Communications Sciences (1925-1980). Contributed by Sam Etler. Processed by Paul Fassbender.

BTL History 7: Transmission Technology 1985

paul-f@verizon.net (Paul F) — Wed, 01 Jun 2022 15:59:59 -0700

825 pages, 83 MB, 500-473, A History of Engineering and Science in the Bell System - Transmission Technology (1925-1975). Missing page 566. Contributed by Sam Etler. Processed by Paul Fassbender.

BTL History 6: Electronics Technology (1925-1975)

paul-f@verizon.net (Paul F) — Sun, 02 Feb 2020 17:01:25 -0800

370 pages, 8MB. A History of Engineering and Science in the Bell System - Electronics Technology (1925-1975). Copyright and First Printing 1985. Chapters on the Transistor, Silicon Integrated Circuits, Electron Tubes, Optical Devices, Magnetic Memories, Piezoelectric Devices, Relays and Switches, Capacitors and Resistors, and Thin-Film Circuits. Contributed, scanned and OCRed by Sam Etler. Cover, bookmarks and size reduction by Karl Brose. Processed by Paul Fassbender.

ATT 1977 - Telecommunications Transmission Engineering

paul-f@verizon.net (Paul F) — Sat, 18 May 2019 10:42:02 -0700

2,098 pages. Communication Engineering is concerned with the planning, design, implementation, and operation of the network of channels, switching machines, and user terminals required to provide communication between distant points.

This three-volume book is written for the practicing Transmission Engineer and for the student of transmission engineering.

Contributed and optimized for viewing on mobile devices by Karl Brose. Processed by Paul Fassbender.

BTL History: Engineering and Operations in the Bell System, 2nd Ed - 1984

paul-f@verizon.net (Paul F) — Wed, 27 Mar 2019 13:49:15 -0700

902 pages. 48MB. Processed and Bookmarked by Steph Kerman.

BTL 1978 - Switching Systems for FAA - Sys 300 301 301A - extract

paul-f@verizon.net (Paul F) — Sat, 02 Feb 2019 22:13:05 -0800

From A History of Engineering and Science in the Bell System - National Service in War and Peace (1925-1975) - 1978
2.3 FAA Air-Route Traffic Control System
2.3.1 No. 300 Switching System

BTL History 1: The Early Years (1875-1925) - 1975

paul-f@verizon.net (Paul F) — Fri, 01 Feb 2019 16:15:33 -0800

1090 pages. 50MB. A History of Engineering and Science in the Bell System - The Early Years (1875-1925). First printing - 1975. Text searchable. Relatively low res images to keep file size low. Find higher resolution images in the version posted on archive.org (about 380MB), but it is missing pages 446-7, 556-7, 664-5, 942-3 and 994-5. Processed by Karl Brose, Jack Ryan, Sam Hallas and Paul Fassbender.

BTL History: The Early Years (1875-1925) - 1975 - ToC, References, Credits and Index - extract

paul-f@verizon.net (Paul F) — Fri, 25 Apr 2014 14:47:21 -0700

From A History Of Engineering and Science In The Bell System - The Early Years (1875-1925). 71 page extract includes Table of Contents, References (27 pages), Credits and Index (28 pages). Bookmarked. Contributed by Steph Kerman.

BTL History 4: Physical Sciences - 1983

paul-f@verizon.net (Paul F) — Sun, 17 Mar 2013 16:15:54 -0700

687 pages. 36MB. A History of Engineering and Science in the Bell System. Physical Sciences (1925 - 1980), 1983. Contributed by Sam Etler, with post-processing by Clint Gilliland.

BTL History 3: Switching Technology - 1982

paul-f@verizon.net (Paul F) — Sun, 17 Mar 2013 16:15:54 -0700

652 pages. 34MB. A History of Engineering and Science in the Bell System. Switching Technology (1925 - 1975), 1982. Contributed by Sam Etler, with post-processing by Clint Gilliland.

AT&T Events In Telephone History - 1974

paul-f@verizon.net (Paul F) — Fri, 29 Jun 2012 13:53:42 -0700

94 pages. 43MB. One of several issues published (and expanded) between 1958 and 1992. Contributed by Steve Cichorsky. OCR by Clint Gilliland.

BTL 1975 - Switching: Step-by-Step Improvements - extract

paul-f@verizon.net (Paul F) — Wed, 28 Oct 2009 06:58:25 -0700

From A History of Engineering and Science in the Bell System: Switching Technology. 16-page extract titled Step by Step Improvements (pages 22-37).
WE installed AE switches until production started in 1926. SxS.