(Mirrored from etler.com)

This is a digital reproduction of 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.

• 0. Cover and Contents  (3.6M PDF)
• 1. No. 5 Crossbar - Introduction  (148k PDF)
• 2. No. 5 Crossbar - A Pictoral Summary[02-PictoralSummary.pdf - MISSING]  (14.4M PDF)
• 3. Design Patterns for No. 5 Crossbar  (1.9M PDF)
• 4. Trunking Plan for No. 5 Crossbar  (1.3M PDF)
• 5. No. 5 Crossbar Marker  (300k PDF)
• 6. Equipment Arrangements for No. 5 Crossbar Markers  (1.9M PDF)
• 7. No. 5 Crossbar Frames  (3.7M PDF)
• 8. The Originating Dial Pulse Register Circuit for the No. 5 Crossbar System  (344k PDF)
• 9. Trunk Selection by No. 5 Crossbar Markers  (1.5M PDF)
• 10. Traffic Distribution in the No. 5 Crossbar Marker  (1.3M PDF)
• 11. Connectors for the No. 5 Crossbar System  (2.4M PDF)
• 12. Senders for No. 5 Crossbar  (2.7M PDF)
• 13. Sender Link Frames for No. 5 Crossbar  (1.9M PDF)
• 14. Incoming Register Link for No. 5 Crossbar  (1.1M PDF)
• 15. Incoming Register Circuits for No. 5 Crossbar  (1.8M PDF)
• 16. Register and Sender Frames in No. 5 Crossbar (3.0 MB)
  
• 17. Number Group Frame for No. 5 Crossbar (1.9M PDF)
• 18. Ringing Selection in No. 5 Crossbar  (1.0M PDF)
• 19. Message Register Operation in No. 5 Crossbar  (1.0M PDF)
• 20. Operator Connections in No. 5 Crossbar  (184k PDF)
• 21. Cold-Cathode-Tube Test Set  (1.6M PDF)
• 22. Maintenance Facilities for the No. 5 Crossbar System  (1.0M PDF)
• 23. The Automatic Monitor  (240k PDF)
• 24. Trouble Recording for the No. 5 Crossbar System  (2.1M PDF)
• 25. Register and Sender Testing in No. 5 Crossbar  (952k PDF)
• 26. Permanent Signals in No. 5 Crossbar  (296k PDF)
• 27. Pulse Conversion in No. 5 Crossbar  (160k PDF)
• 28. Alarm System for No. 5 Crossbar  (968k PDF)
• 29. Interoffice Transfer of Alarms in No. 5 Crossbar  (252k PDF)
• 30. No. 5 Crossbar AMA Translator  (2.7M PDF)
• 31. Pretranslation in No. 5 Crossbar  (1.3M PDF)
• 32. Traffic Registers for No. 5 Crossbar  (3.1M PDF)