[time-nuts] 60Hz mains clocking in computers

[Poul-Henning Kamp]

In message <3058527A-CC99-4174-BE75-21DD92334155 at astro.berkeley.edu>, Colby Gut
ierrez-Kraybill writes:
>
>I'm trying to get to the bottom of whether or not any computing  
>equipment made around the advent of UNIX systems (or any time-slicing  
>system) used the mains cycles of 60Hz as phase lock for the internal  
>system clock. 

They sure did.  Digitals PDP computers had a counter register
which counted mains-cycles as the only sort of real-time-clock.

-- 
Poul-Henning Kamp       | UNIX since Zilog Zeus 3.20
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