Folder No. 5 Crossbar book

This is a digital reproduction of a book published by Bell Labs containing a number of articles from 1949 to 1951 that detail most aspects of the No. 5 Crossbar. The articles were all publised in the Bell Laboratories Record.

The entire book is 150 pages. Due to the large number of images the book is presented with each article in a separate PDF. This makes the file sizes more manageable. Scanned and converted to PDF by Sam Etler.

Documents

Select Toggle Title Date Download
pdf 00-Contents (1186 downloads) Popular Download (pdf, 3.60 MB)
pdf 01-Introduction (894 downloads) Popular Download (pdf, 145 KB)
pdf 02-PictoralSummary (888 downloads) Popular Download (pdf, 14.36 MB)
pdf 03-DesignPatterns (756 downloads) Popular Download (pdf, 1.93 MB)
pdf 04-TrunkingPlan (771 downloads) Popular Download (pdf, 1.32 MB)
pdf 05-Marker (854 downloads) Popular Download (pdf, 298 KB)
pdf 06-EquipmentArrangements (668 downloads) Popular Download (pdf, 1.90 MB)
pdf 07-Frames (733 downloads) Popular Download (pdf, 3.69 MB)
pdf 08-OriginatingDPRegister (683 downloads) Popular Download (pdf, 340 KB)
pdf 09-TrunkSelection (621 downloads) Popular Download (pdf, 1.47 MB)
pdf 10-TrafficDistribution (620 downloads) Popular Download (pdf, 1.33 MB)
pdf 11-Connectors (665 downloads) Popular Download (pdf, 2.37 MB)
pdf 12-Senders (674 downloads) Popular Download (pdf, 2.72 MB)
pdf 13-SenderLinkFrames (628 downloads) Popular Download (pdf, 1.87 MB)
pdf 14-IncomingRegisterLink (633 downloads) Popular Download (pdf, 1.05 MB)
pdf 15-IncomingRegisterCircuits (626 downloads) Popular Download (pdf, 1.81 MB)
pdf 16-RegisterAndSenderFrames (568 downloads) Popular Download (pdf, 3.03 MB)
pdf 17-NumberGroupFrame (617 downloads) Popular Download (pdf, 1.93 MB)
pdf 18-RingingSelection (734 downloads) Popular Download (pdf, 1.02 MB)
pdf 19-MessageRegisterOperation (577 downloads) Popular Download (pdf, 1019 KB)

New User?

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

Recent Contributors

Thanks for new documents from Ed Palazzo, Bruce Patterson, Jon Kolger, Paul Ivester, Len Hicken, Paul Fassbender, Fred Haynes, Kurt Rudolph, Wade ("Kellogg KITT"), the Connections Museum, Rick Walsh, Jeff Lamb, Jeremy Walters, Mark Cuccia, Alan David, Harry Joseph, Charlie Terry, Karl Brose, Dennis Hock, Tim Griffin, Remco Enthoven, and Steve Cichorsky.

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

30 Latest Additions

Who's online

We have 391 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.