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Figure 8-5: Effects of Resistance on Charging Rate
You normally issue POTGO at the beginning of a video screen, then read the values in the
POT registers during the next vertical blanking period, just before issuing POTGO again.
Nothing in the system prevents the counters from overflowing (wrapping past a count of
255). However, the system is designed to insure that the counter cannot overflow within
the span of a single screen. This allows you to know for certain whether an overflow is
indicated by the controller.
PROPORTIONAL CONTROLLER REGISTERS
The following registers are used for the proportional controllers:
POT0DAT - port 1 data (vertical/horizontal3
POT1DAT - port 2 data (vertical/horizontal)
Bit positions:
Bits 15-8 POT0Y value or POT1Y value
Bits 7-0 POT0X value or POT1X value
All counts are reset to zero when POTGO is written with bit zero high. Counts are normally
read one frame after the scan circuitry is enabled.
- 230 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...