Read pixel value

OSWord call Action Available on:
(dec) (hex)BBC Master Electron
9 09 Read pixel valuex x x

This routine returns the status of a screen pixel at a given pair of X and Y co-ordinates.

Parameter block

XY+ Content
0 LSB of X coordinate
1 MSB of X coordinate
2 LSB of Y coordinate
3 MSB of Y coordinate
4 Logical colour at that point

On exit, XY+4 contains the logical colour at the required point or &FF if the point specified was off the screen.