On 3/10/2023 6:11 PM, Fred Cisin via cctalk wrote:
On Fri, 10 Mar 2023, Kevin Anderson via cctalk wrote:
I always thought of the distinctions this way (from my basis of
exposure from late 1970s through the 1980s) and from a higher
educational setting primarily:
Mainframe = repairs required multiple technicians, some possibly
there full-time; regular operator(s) present, and a locked door
located between you and the machine; entire specialized room with
raised flooring, extra-high amperage specialized power sources and
wiring, and significant air conditioning
Minicomputer = Vendor still provides a technician (just one) for
repairs, who drives in out in a station wagon; only a part-time
operator only; an user can be located in the same room; 240-volt
wiring, but not particularly outlandish
Microcomputer = Computer can sit on a desk or in a "normal" room;
broken computer taken by user to someplace to be repaired or
self-repaired; typically one user, and only 120-volt household or
office power needed.
Supercomputer = a really fast and specialized version (primarily
focusing on high-speed mathematical computations) of a mainframe.
extension cord / dedicated circuit / dedicated pole transformer
Which machines needed 3-phase?
Some PDP-11's although you can sometimes break them up and just use
lots of 110/220 outlets. And then you get to watch the lights in the house
dim when you fire them up.
Some Vaxen as well and some of those you cannot break up. At least I never
figured out how. But the University electricians always did a good job
of meeting
my power needs.
I would be willing to bet that the 1401, 360's and 4300 systems all
required a bit
more than you get out of a standard 100AMP 220 volt electrical feed.
And Univac 1100's didn't run on commercial power at all but required a motor
generator between them and commercial power.
bill
