"the well known plotting bugs of the original 4010"

Tim Shoppa shoppa_classiccmp at trailing-edge.com
Fri Jan 20 18:47:30 CST 2006

Richard <legalize at xmission.com> wrote:

> <http://www.rdrop.com/~jimw/jcgm-io.shtml#IO%20Devices> drops this
> phrase in the discussion of add-ons to the Heathkit H-19 video
> terminal.
> Just what were "the well known plotting bugs of the original 4010"?
> Since I have a 4010, I'm keen to know :-)

The necessary delay between doing an erase and starting
to draw again (a second or two), or the bright blink when you erase?

You can only erase the entire screen?

Overwrite doesn't replace a character, but actually just draws
over it leaving the old character behind?

Lack of scrolling ability?

Funny things happen if you send graphics coordinates too fast
(making the "short mode addressing" useless at high speeds?)

Didn't it also use RC networks for the serial clock, and there
was a pot to tweak? That was the thing that struck me as being
really chintzy at the time, but there was that pot for rubbering
the frequency...

GIN mode? (And the other GIN mode?) And the funny characters that
could come out that some minicomputer OS's just did not get along with?

Of course, to you and me these are just intrinsic characteristics
of a 4010, but to someone who grew up with non-storage-scope
CRT's they probably could be frustrating.


More information about the cctalk mailing list