Toll Switching System No. 4A Sequence Charts, Operational Sketches and
Reference Material, Various Dates

A128.819, Checking List - BSP MP Items Covering Sequence Charts,
Operational Sketches, and Associated Reference Material - No. 4A or 4M
Toll Switching System, Issue 5, Jan. 1954

Sequence charts, operational sketches and associated reference material. (Central Office Maintenance)

Checking List, BSP MP Items covering sequence charts, operational sketches and associated reference material. (Central Office Maintenance)

Test Number Directory. Contributed by Steve Cichorsky. Processed by Remco Enthoven and Paul Fassbender.

Contributed by Steve Cichorsky.  OCR by Clint Gilliland

Contributed by Steve Cichorsky. Processed by Remco Enthoven and Paul Fassbender.

Contributed by John Novack.

Contributed by: Remco Enthoven

From the collection of the JKL Museum of Telephony

Contributed by: Remco Enthoven

From the collection of the JKL Museum of Telephony

May 1952. (Renumbered to 852-220-100 i1) 500 series design objectives, mechanical, electrical and transmission features, noise crosstalk and sidetone considerations in design and performance.

PTT: Pacific Tel & Tel. Contributed by Clint Gilliland.

Contributed by John Stancliff.

Contributed by John Stancliff.

Contributed by John Stancliff.

Contributed by John Novack.

Contributed by Steve Cichorsky. OCR by Clint Gilliland.

Contributed by Steve Cichorsky.  OCR by Clint Gilliland.

624 pages. Collection of H-series "BUILDINGS" BSPs from 1932-1960. Includes an alpha index plus several numeric checking lists. The 1945 list includes some WR- (Wartime) BSPs, which (unfortunately) are not in the collection. If you have some of these, please contribute copies. BSPs are bookmarked by number, so use the index docs -- as you would with a paper archive. Note that the collection contents do not match the index documents, so refer to the bookmarks for the actual contents. Contributed by John Jones. Scanned and OCRed by John Novack.