You are here: Home > Browse the Library > BSP - Bell System Practices (by Doc #) > BSP Categories by early Letter Code (by Doc #) > A837.002 i1 Apr 1936 General Description 640-line and 1440-line no. 12 Switchboard

Check out the TCI YouTube channel here. Please subscribe!

Check here for the Upcoming Telephone Shows

pdf A837.002 i1 Apr 1936 General Description 640-line and 1440-line no. 12 Switchboard Popular

2399 downloads

Download (pdf, 4.03 MB)

A837.002-i1-apr-1936-general-description-640-line-1440-line-no.12-switchboard.pdf

Contributed by: Remco Enthoven

From the collection of the JKL Museum of Telephony

New User?

Read the articles under "Introduction" in the black menu bar above.

Recent Contributors

Thanks for new documents from Tim Fox, Andrew Cook, Steph Kerman, Jason Anderson, Doug Duffy, Bruce Patterson, Jeremy Walters, Nick Hunseder, Ed Burnett, Ralph Meyer, Shane Young, David Brown, the Connections Museum, Paul Fassbender, Lou Maffei, Rick Thoensen, Sheila Flory, Tom Hesson, Jim Hurtle, Ed Palazzo, Remco Enthoven, Jon Kolger, Paul Ivester, and Len Hicken.

Please send a file to add your name to this list!

30 Latest Additions

Who's online

We have 518 guests online

Hints for using the TCI Library

"Menu Bar" for site navigation.
Many menu choices are hidden until you mouse over words in the black Menu Bar (above).  If you want help getting started, see the links under the word "Introduction" in the Menu Bar.
 
The user interface is oriented toward the user’s choice to either Browse or Search for information.  The Browse the Library menu entry offers many quick links to move around the Library quickly.  Try it!

Three search options.
The Library’s keyword-based searches, called Basic Search and Advanced Search, accept keywords as short as 2 characters (WE, AE, etc.) and search strings up to 255 characters.  If you get more than 1,000 items, refine your search or try the Google Search option.
 
When selected from the Menu Bar, Google only searches for files in the TCI Library.
 
Library INBOX.
The INBOX may hold some files that have been submitted but not fully processed into the Library.  These are often topics of current discussion on the TCI Email Group. Items in the INBOX are not found using Basic or advanced searches, but ARE found by a Google Search.
 
Remember to check the INBOX if you don't find something with the other searches.
 
Finding BSPs.
Many BSPs are currently only identified by BSP number. If a text search doesn’t produce a BSP, try looking in one of the many BSP index documents to find a BSP number for the product you are researching just as you would do if referencing a paper library of the BSPs. Then enter the BSP number in the search box.
 
Finding CDs and SDs.
Some related CDs and SDs are filed in different areas. Try searching for just the numeric portion of the name.  Remember to check the INBOX if you don't find something with the Basic or Advanced searches -- or use the Google search.
 
Compact Category Listing.
When browsing, to change the category listing view from normal to compact, click on Browse the Library in the black menu bar.
 
To change from compact to normal view, click on Document Repository in the drop down under Browse the Library.