7 Oct
2004
7 Oct
'04
12:59 p.m.
On Thu, 7 Oct 2004, Bob Shannon wrote:
Is anyone on the list familiar with vector display
monitors?
Not specifically, but related:
I read 'The Secret Life of Vector
Generators", and notices that Atari vector
generators 'rest' the beam at the center of the screen. There is a comment
about
doing this to prevent the deflection amp transistors from smoking.
But the HP 1350 graphics translator 'rests' the beam at the lower left hand
corner of the screen, not the center.
If the generator turns off write current (eg. Z axis off) when
"at rest" you can let the beam rest whereever you want. If it's
a 4-quadrant system eg. location (0, 0) is X=0V, Y=0V, you can
simply multiply X and Y by 0 when Z=0, aka turn off X and Y.
If you're simultaneously translating from 4-quadrant to
1-quadrant (eg. (0, 0) is X=0V, Y=0V) then you can force X=Y=
(fullscale / 2) whenever Z is off.
Both schemes could be done with an opamp each dimension,
probably re-use one already present.