[cctalk] Re: mainframe vs mini

[Paul Koning via cctalk]

> On Mar 10, 2023, at 6:32 PM, Chuck Guzis via cctalk <cctalk@classiccmp.org> 
> wrote:
> 
> On 3/10/23 15:11, Fred Cisin via cctalk wrote:
> 
> 
>> extension cord / dedicated circuit / dedicated pole transformer
>> 
>> Which machines needed 3-phase?
> 
> Extra points for requiring an MG set furnishing 400Hz 3-phase.
> 
> --Chuck

CDC 6000 series is the one I know of.  But they'd also use either 1 or 3 phase 
regular 50/60 Hz power.  For example, the console display uses 3 phase 400 Hz 
for its power supplies (nice for low ripple) and 60 Hz 110 V for fans.  The CPU 
cabinet takes 400 Hz power to run its power supplies but 60 Hz power for the 
compressors that cool the Freon that cools the logic.

As for 3 phase, PDP-11 CPUs did not, but some of the disk drives (like RP06) do 
since they use 3 phase induction motors to drive the spindle.

        paul