To be really picky about it, I spent quite a few years as a video
engineer (I even designed a monitor!), and I know of no way that
the monitor itself could not display a continuous greyscale. The
"video amplifier" circuitry can certainly be set up (as in the
MDA) to respond only to certain signal levels. This saves the
cost of an analog-to-digital converter. Remember that many of the
"experts" at IBM didn't expect the PC to be any more than an ex-
pensive toy! Of course, it may not be.
Ken Martwick
