Common operational misconceptions

Sat Feb 18 07:19:21 UTC 2012

"Ethernet/Token Ring/Cisco Console/whatever uses an RJ45 connector"

 RJ45 defines a keyed 8P8C type connector, wired in a specific
 manner, for a specific 2 wire telco service. Incompatible with the
 above on several levels.  "RJxx" == specific connector/wiring pattern 
 for specific telco applications. Non-telco uses need not apply.

 One of these days I'm going to start carrying around some actual RJ45
 type cables to hand out to those who ask.

"DB9"

 DB defines a D series subminiature connector with a size "B" (nominal 25 pin) 
 shell. DE defines a size "E" (nominal 9 pin) shell. DA15, DB25, DC37, DD50,
 DE9, etc..  Also DB13W3 (old Sun monitors), etc. If in doubt, refer to 
 ITT/Cannon catalogs. (my oldest is from 1971).

-- 
               -- Welcome My Son, Welcome To The Machine --
Bob Vaughan  | techie@{w6yx|tantivy}.stanford.edu 	| techie at tantivy.net
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