1 May
2006
1 May
'06
12:13 p.m.
-----Original Message-----
From: cctalk-bounces at classiccmp.org [mailto:cctalk-bounces at classiccmp.org]
On Behalf Of Don North
Sent: Monday, May 01, 2006 12:24 AM
To: General Discussion: On-Topic and Off-Topic Posts
Subject: Re: 19" Rack History
I currently work for a big datacom supplier, and
design a lot of rack
mount equipment. The current major datacom/telecom customers invariably
want all equipment to fit in standard 19" two or four post racks. They
really don't like the 23" width (not 24" width) at all, and really balk
at buying a chassis that requires a 23" rack.
More interesting is the concept of 'U' when it comes to racks. All
equipment is in units of 'U' (a standard 8' rack is 44U), which is
1.75". So anyone know where 'U' came from, and why it is called
'U'?
AK6DN
Even more confusion was added by DEC when they created the 5.25" tall
"System unit" standard - i.e. any 5.25" high box like a BA23 etc.
So, if you enjoy confusing people, or just want to correct somebody for no
reason, start a debate that a 2U device is 10.5" tall :)