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CONNECTOR PIN USAGE FOR FIRE BUTTON INPUTS
PIN MNEMONIC DESCRIPTION
--- -------- -----------
1 -x-
2 -x-
3 -x-
4 -x-
5 -x-
6 FIRE* Left mouse button/fire button
7 -x-
8 ground
9 -x-
GAME PORT INTERFACE TO PROPORTIONAL CONTROLLERS
Resistive (potentiometer) element linear taper proportional
controllers are supported up to 528k Ohms max (470k +/- 10%
recommended). The JOY[0/1]DAT registers contain digital
translation values for y in the high byte and x in the low byte.
A higher count value indicates a higher external resistance.
The Amiga performs an integrating analog-to-digital conversion
a follows:
1. For the first 7 (NTSC) or 8 (PAL) horizontal display lines,
the analog input capacitors are discharged and the positions
counters reflected in the POT[0/1]DAT registers are held reset.
For the remainder of the display field, the input capacitors are
allowed to recharge through the resistive element in the external
control device.
2. The gradually increasing voltage is continuously compared to
an internal reference level while counter keeps track of the
number of lines since the end of the reset interval.
3. When the input voltage finally exceeds the internal threshold
for a given input channel, the current counter value is latched
into the POT[0/1]DAT register corresponding to that channel.
4. During the vertical blanking interval, the software examines
the resulting POT[0/1]DAT register values and interprets the
counts in terms of joystick position.
NOTE: The POTY and POTX inputs are designated as "right mouse button" and
"unused mouse button" respectively. An opened switch corresponds to high
resistance, a closed switch to a low resistance. The buttons are also
available in POTGO and POTINP registers. It is recommended that
ROM kernel calls be used for future hardware compatibility.
It is important to realize that the proportional controller is more of a
"pointing" device than an absolute position input. It is up to the
software to provide the calibration, range limiting and averaging functions
needed to support the application's control requirements.
The POT[0/1]DAT register are typically read during video blanking,
but MAY be available prior to that.
- 308 Appendix E -
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...