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Copyright 1991 David Jurgens |
INT 10,4 - Read Light Pen Position
AH = 04
on return:
AH = 0 light pen switch not triggered
= 1 light pen triggered
BX = pixel column (0-319 or 0-639, mode dependent)
CH = raster line (0-199) (CGA and EGA modes 4, 5 and 6)
CX = raster line (EGA modes except 4, 5 and 6)
DH = row (0-24)
DL = column (0-79 or 0-79 mode dependent)
- data returned as a byte coordinate, leaving horizontal
accuracy to within 2 pixels (320) or 4 pixels (640)
- vertical accuracy within 2 lines
- PS/2's don't support the light pen interface
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| Esc or Alt-X to exit |
int 10,4 |
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