I was an intern at Tektronix around '79-80. Have
you ever run across
any scraps of info about the Tek 4016, 4081 or 4027?
Used an under-powered eight bit micro (8085?) to
interpret
a complex serial command language and draw the graphics.
I used one around 1980. Graphics were constructed using a programmable
character generator, a la the Intecolor. It was similar to the 4025,
which is mono, which I do have info on at
http://bitsavers.org/pdf/tektronix/402x
I've been looking for technical/service docs for the 4027 and 411x/412x series
for a while now.