The most famous computer that never was.
PDP-10 computers running the TOPS-10 operating system
were labeled `DECsystem-10' as a way of differentiating them from
the PDP-11. Later on, those systems running TOPS-20 were labeled
`DECSYSTEM-20' (the block capitals being the result of a lawsuit
brought against DEC by Singer, which once made a computer called
`system-10'), but contrary to popular lore there was never a
`PDP-20'; the only difference between a 10 and a 20 was the
operating system and the color of the paint. Most (but not all)
machines sold to run TOPS-10 were painted `Basil Blue', whereas
most TOPS-20 machines were painted `Chinese Red' (often mistakenly
-- does it take to change a light bulb?
100-one to announce that it burned out, 10 to agree, 20
to come running in with new light bulbs and screw them
in, 9 to screw them in and leave the old bulb in, 10 to
ask for a videotape of the screwing, another one to come
in a few minutes later and notice the bulb went out
again and start the whole process all over again....