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READING MOUSE/TRACKBALL CONTROLLERS
Pulses entering the mouse inputs are converted to separate horizontal and vertical counts.
The 8 bit wide horizontal and vertical counter registers can track mouse movement
without processor intervention.
The mouse uses quadrature inputs. For each direction, a mechanical wheel inside the
mouse will produce two pulse trains, one 90 degrees out of phase with the other (see
Figure 8-2 for details). The phase relationship determines direction.
The counters increment when the mouse is moved to the right or "down" (toward you).
The counters decrement when the mouse is moved to the left or "up" (away from you).
MOUSE QUADRATURE
V VQ : D1 D0
----------------
0 0 : 1 0
0 1 : 0 1
1 0 : 1 1
1 1 : 0 0
Case 1: Count up
________ ________ ________ ____
/ \ / \ / \ /
V ____/ \________/ \________/ \________/
________ ________ ________
/ \ / \ / \
VQ ________/ \________/ \________/ \__________
____ ____ ____ ____ ____ ____
/ \ / \ / 1 \ 0 / \ / \ /
D0 ____/ \____/ \____/ \____/ \____/ \____/
D1 ________ ________ ________ _________
\ / 1 \ 0 / \ /
\________/ \________/ \________/
Case 2: Count down
________ ________ ________ ____
/ \ / \ / \ /
V ____/ \________/ \________/ \________/
VQ ________ ________ ________ ________
\ / \ / \ /
\________/ \________/ \________/
D0 ____ ____ ____ ____ ____ ____
\ / \ / \ / \ / \ / \
\____/ \____/ \____/ \____/ \____/ \____
________ ________ ________
/ \ / \ / \
D1 ________/ \________/ \________/ \________
D2 ____
\
\____ etc.
Figure 8-2: Mouse Quadrature
- 224 Interface Hardware -
Содержание Amiga A1000
Страница 1: ...AMIGA HARDWARE REFERENCE MANUAL 1992 Commodore Business Machines Amiga 1200 PAL...
Страница 20: ...Figure 1 1 Block Diagram for the Amiga Computer Family Introduction 11...
Страница 21: ...12 Introduction...
Страница 72: ...Figure 3 12 A dual Playfield display Playfield Hardware 63...
Страница 87: ...Figure 3 24 Horizontal Scrolling 78 playfield hardware...
Страница 101: ...92 Playfield Hardware...
Страница 199: ...Figure 6 9 DMA time slot allocation 190 Blitter hardware...
Страница 203: ...Figure 6 13 Blitter Block Diagram 194 Blitter Hardware...
Страница 229: ...220 System Control Hardware...
Страница 246: ...Figure 8 8 Chinon Timing diagram cont Interface Hardware 237...
Страница 265: ...256 Interface Hardware...
Страница 289: ...280 Appendix A...
Страница 297: ...288 Appendix B...
Страница 298: ...APPENDIX C CUSTOM CHIP PIN ALLOCATION LIST NOTE Means an active low signal Appendix C 289...
Страница 302: ...APPENDIX D SYSTEM MEMORY MAP Appendix D 293...
Страница 343: ...334 Appendix F...
Страница 351: ...342 Appendix G...
Страница 361: ...352 Appendix H...
Страница 367: ...358 Appendix I...