Trackball: Difference between revisions

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[[File:Irrmaze_bios1.png|right]]
[[File:Irrmaze_bios1.png|right]]


Controller type used only by [[The Irritating Maze]].
Special controller only used in [[The Irritating Maze]] cabs.


Sort of an upside-down mechanical mouse, uses two optical encoders handled by the [[SIT board]].
Works the same way as an upside-down mechanical mouse. Uses two optical encoders for X and Y movement, handled by the [[SIT board]].


Special [[System ROM]]: 236-bios.sp1. X counter in {{Reg|REG_P1CNT}} when bit 0 of {{Reg|REG_POUTPUT}} is 0, otherwise Y counter.
A special [[system ROM]] is used (236-bios.sp1).
Refreshed every vblank unconditionnaly by this System ROM.
 
The counter values are read from {{Reg|REG_P1CNT}}:
 
* The X counter value when bit 0 of {{Reg|REG_POUTPUT}} is 0.
* The Y counter value when bit 0 of {{Reg|REG_POUTPUT}} is 1.
 
Speed and direction are computed from the counter deltas.


[[Category:Cartridge systems]]
[[Category:Cartridge systems]]

Latest revision as of 18:22, 13 March 2017

Special controller only used in The Irritating Maze cabs.

Works the same way as an upside-down mechanical mouse. Uses two optical encoders for X and Y movement, handled by the SIT board.

A special system ROM is used (236-bios.sp1).

The counter values are read from REG_P1CNT:

Speed and direction are computed from the counter deltas.