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Kempston Mouse

463 bytes added, 18:37, 1 October 2015
/* Technical */
chooses this.
Position:
Port FBEEh READ: Kempston Mouse 8 bit X position (left: -ve, right: +ve)
Port FBEFh READ: Kempston Mouse 8 bit Y position (up: +ve, down: -ve)
Number of NOTE: * The position values aren't reset after reading.* The position values do not change if the mouse buttons supported doesn't move in that * Position values wrap around e.g. when moving left with movement speed of 1, 0 wraps around to be confirmedff (0-1 -> ff)and when moving right with movement speed of 1, ff wraps around to 0 (ff+1->0) To calculated the distance moved since last read subtract the new value read from the previous value read and AND with ff. The value is the amount of movement.0 means no movement. -ve means moving left/down, +ve means right/up.
Position:
Port FBEEh READ: Kempston Mouse 8 bit X position
Port FBEFh READ: Kempston Mouse 8 bit Y position
Note: The position values aren't reset after reading.
To calculated the distance since last read:
dist=new-old, old=new
whereas,
Buttons:
Port FAEFh READ: Kempston Mouse Buttons
bit 0: Left Right Button (active low) bit 1: Right Left Button (active low) bit 2..7: unknownnot used. report as high (1)
== Review (German) ==
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