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KEYCODES
Each key has a keycode associated with it (see accompanying Table). Keycodes are
always 7 bits long. The eighth bit is a "key-up"/"key-down" flag; a 0 (high level) means
that the key was pushed down, and a 1 (low level) means the key was released (the CAPS
LOCK key is different – see below).
For example, here is a diagram of the "B" key being pushed down. The keycode for "B" is
$35=00110101; due to the rotation of the byte, the bits transmitted are 01101010.
___ ___ ___ ___ ___ ___ ___ ___ _______
KCLK \_/ \_/ \_/ \_/ \_/ \_/ \_/ \_/
_______ ______ ______ ____________
KDAT \__________/ \____/ \____/
0 1 1 0 1 0 1 0
In the next example, the "B" key is released. The keycode is still $35, except that bit 7 is
set to indicate "key-up," resulting in a code of $B5 = 10110101. After rotating, the
transmission will be 01101011:
___ ___ ___ ___ ___ ___ ___ ___ _______
KCLK \_/ \_/ \_/ \_/ \_/ \_/ \_/ \_/
_______ ______ ______ ______
KDAT \__________/ \____/ \__________/
0 1 1 0 1 0 1 0
CAPS LOCK KEY
This key is different from all the others in that it generates a keycode only when it is
pushed down, never when it is released. However, the up/down bit is still used. When
pushing the CAPS LOCK key turns on the CAPS LOCK LED, the up/down bit will be 0;
when pushing CAPS LOCK shuts off the LED, the up/down bit will be 1.
- Appendix H 345 -
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...