[RTTY] When did mechanical teleprinters become obsolete?

[Russmill47@aol.com]

When I left Western Union in 1985, the Digital Exchange System (DES) which  
combined the former AT&T TWX system with the Telex system in the USA, had  tens 
of thousands of end devices in commercial (business) service.  These  were 
mostly 28, 32, 33 and 35 Teletype machines.  But there were also  Siemens T-100 
and T-1000 machines in service.   A similar network, run  by CNCP existed in 
Canada.  And each Postal system, around the world, had  similar five level 
Telex networks.
 
I lost touch with any statistics about the Telex network after 1985 but the  
number of Telex and TWX terminals were decreasing as businesses replaced Telex 
 and TWX with Fax machines.
 
Russ
WA3FRP