Changes

AMX Mouse

1,178 bytes added, 21:30, 8 January 2010
The tape software is : [[AMX Art]].
 
== Technical ==
 
The AMX Art software uses the CPC's 300Hz interrupt to read the joystick port (at least it tries to do that, while moving the mouse pointer, the software accidently disables IRQs, and so, misses some interrupts). This is giving it a relative low resolution of max 300 mickeys per second (or actually less, due to the missed IRQs).
 
The AMX Interface hardware basically converts the incoming mouse signals to joystick signals, presumably issuing a LOW pulse (per mickey) on the direction lines, like so:
 
Row9.Bit0 Joy1up LOW for 1/300s per mickey, when mouse moved up
Row9.Bit1 Joy1down LOW for 1/300s per mickey, when mouse moved down
Row9.Bit2 Joy1left LOW for 1/300s per mickey, when mouse moved left
Row9.Bit3 Joy1right LOW for 1/300s per mickey, when mouse moved right
Row9.Bit5 Joy1fire1 LOW when Right mouse button pressed
Row9.Bit4 Joy1fire2 LOW when Left mouse button pressed
Row9.Bit6 Joy1fire3 LOW when Middle mouse button pressed
 
Note: The exact hardware timings are '''unknown''', the values "1/300s" in the above description assumes that the mouse '''hardware''' is designed to match up with the 300Hz '''software''' timings.
== Covers ==
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