360/50 microcode listing

Paul Koning paulkoning at comcast.net
Thu May 7 12:41:04 CDT 2015

> On May 7, 2015, at 1:16 PM, Jon Elson <elson at pico-systems.com> wrote:
> ...
> You can't do that with a real 360 (some 360/20's were pretty small), even a 360/30 was a pretty big box.  And, you can't run a 360 off normal residential power, either.  Many of the peripherals used 3-phase motors, and hacking the converter/inverter to run off single phase would not be a task for any but the most experienced EE.

That isn’t really true; hasn’t been for a long time, and even less so in recent decades.  Home machinery operators have used “phase converters” for ages to drive machinery like lathes that use three-phase motors.  A rotary converter is basically just a three-phase motor modified to run from one phase power across one of its windings — it delivers the three phases at the three winding terminals.  And nowadays you can get a “variable frequency motor drive” which is in effect a three-phase AC power generator, frequency of your choice within reason.  The smaller ones run off one-phase power.  Either option starts at just a few hundred dollars, and rotary converters can be built from an old three phase motor plus a capacitor or two for much less than that.

Rotary converters would easily feed any three phase powered computer with the exception of CDC mainframes.  A VFD would take care of those (since they want 400 Hz).  All that assumes you can get enough current at home, of course.  At least in the USA, enough current is often pretty easy, while more than one phase is not likely to be doable.


More information about the cctech mailing list