Trackball: Difference between revisions
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(Created page with "right Special BIOS: 236-bios.sp1. X counter in {{Reg|REG_P1CNT}} when bit 0 of {{Reg|REG_POUTPUT}} is 0, otherwise Y counter. Refreshed every v...") |
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[[File:Irrmaze_bios1.png|right]] | [[File:Irrmaze_bios1.png|right]] | ||
Special [[ | 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|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:
- The X counter value when bit 0 of REG_POUTPUT is 0.
- The Y counter value when bit 0 of REG_POUTPUT is 1.
Speed and direction are computed from the counter deltas.