[177500] in North American Network Operators' Group
Re: REMINDER: Leap Second
daemon@ATHENA.MIT.EDU (TR Shaw)
Sun Jan 25 18:43:00 2015
X-Original-To: nanog@nanog.org
From: TR Shaw <tshaw@oitc.com>
In-Reply-To: <20150125230649.GA90136@pit.databus.com>
Date: Sun, 25 Jan 2015 18:42:51 -0500
To: Barney Wolff <barney@databus.com>
Cc: nanog@nanog.org
Errors-To: nanog-bounces@nanog.org
On Jan 25, 2015, at 6:06 PM, Barney Wolff <barney@databus.com> wrote:
> On Sun, Jan 25, 2015 at 02:24:52PM -0800, Stephen Satchell wrote:
>>=20
>> Today's computers don't use clocks derived from 50- or 60-hertz
>> power-line frequency. The last computer I remember seeing with such =
a
>> clock was the IBM System/360. The System/370 used a motor-generator =
set
>> for the power supply, so it had to get its real-time clock time =
source
>> another way.
>=20
> The 360/95 and /91 also used 400 Hz from a motor/gen. Water cooled, =
too.
> One of my fondest war stories is when the power was turned off for =
July 4th
> weekend but the water was left on.
That made the transformers smaller/cooler and more efficient. I seem to =
remember a 195 as well but maybe it is just CRS.
