Quantum Data 801GC, 801GF, 801GX, Руководство владельца и программиста

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4-47
Persist
Description In the primary version, 15 small white boxes move
back and forth between diagonal guide lines. The
lines form 15 side-by-side tracks. The size of each
box is scaled to the light meter box size set by the
MSIZ system parameter. The box in the center track
moves one scan line vertically and one pixel
horizontally for each vertical frame of refresh. The
seven boxes in the tracks to the right of the center
track move 2, 3, 4, 5, 6, 7 and 8 pixels and lines
per frame. These boxes are marked 2X through
8X at the bottom of the tracks. The seven boxes to
the left of the center track move one scan line
vertically and one pixel horizontally for every 2,
3, 4, 5, 6, 7 and 8 vertical frames of refresh. These
boxes are marked /2 through /8 at the bottom of
the tracks.
In cases where the next move would cause the
b o x t o m o v e b e y o n d t h e e n d o f i t s t r a c k , i t
i m m e d i a t e l y r e v e r s e s a n d m o v e s t h e c o r r e c t
distance in the opposite direction for the next
frame.
A continuously running counter appears in the
upper left-hand corner of the image. The number
shown is the number of vertical frame refreshes
that have occurred since the generator was first
powered up.
The secondary version draws a black image on a
white background.