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PUTTING TOGETHER A COPPER INSTRUCTION LIST
The Copper instruction list contains all the register resetting done during the vertical
blanking interval and the register modifications necessary for making mid-screen
alterations. As you are planning what will happen during each display field, you may find it
easier to think of each aspect of the display as a separate subsystem, such as playfields,
sprites, audio, interrupts, and so on. Then you can build a separate list of things that must
be done for each sub-system individually at each video beam position.
When you have created all these intermediate lists of things to be done, you must merge
them together into a single instruction list to be executed by the Copper once for each
display frame. The alternative is to create this all-inclusive list directly, without the
intermediate steps.
For example, the bit-plane pointers used in playfield displays and the sprite pointers must
be rewritten during the vertical blanking interval so the data will be properly retrieved
when the screen display starts again. This can be done with a Copper instruction list that
does the following:
WAIT until first line of the display
MOVE data to bit-plane pointer 1
MOVE data to bit-plane pointer 2
MOVE data to sprite pointer 1
and so on
As another example, the sprite DMA channels that create movable objects can be re-used
multiple times during the same display field. You can change the size and shape of the
reuses of a sprite; however, every multiple reuse normally uses the same set of colors
during a full display frame.
You can change sprite colors mid-screen with a Copper instruction list that waits until the
last line of the first use of the sprite processor and changes the colors before the first line
of the next use of the same sprite processor:
WAIT for first line of display
MOVE firstcolor1 to COLOR 17
MOVE firstcolor2 to COLOR 18
MOVE firstcolor3 to COLOR 19
WAIT for last line +1 of sprite's first use
MOVE secondcolor1 to COLOR 17
MOVE secondcolor2 to COLOR 18
MOVE secondcolor3 to COLOR 19
and so on
- 22 Coprocessor 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...