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Unused |
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This routine plots the path of a star with point of origin (100,100) and direction (10,10).
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| 38844 | LD BC,2570 | Load B with 10 (y-component of star's direction) and C with 10 (x-component of direction) | ||
| 38847 | LD DE,25700 | Load D with 100 and E with 100 (initial coordinates of star) | ||
| 38850 | LD IX,25614 | Point IX at start of table of stars' movement data | ||
| 38854 | PUSH DE | Store DE | ||
| 38855 | CALL 39016 | Set up star's movement data based upon starting position and direction | ||
| 38858 | POP DE | Restore DE | ||
| 38859 | LD (IX+0),E | Set initial x-coordinate of star | ||
| 38862 | LD (IX+1),D | Set initial y-coordinate of star | ||
| 38865 | LD B,50 | Load B with 50 (as loop runs 50 times) | ||
| 38867 | PUSH BC | Store BC | ||
| 38868 | CALL 39081 | Load BC with new (y,x) coordinates of a star depending upon the signs and magnitudes of its direction | ||
| 38871 | LD (IX+0),C | Load C (x-coordinate to PLOT) into star's x-coordinate | ||
| 38874 | LD (IX+1),B | Load B (y-coordinate to PLOT) into star's y-coordinate | ||
| 38877 | CALL 8933 | PLOT the pixel (x=C, y=B) | ||
| 38880 | POP BC | Restore BC (B = remaining number of iterations) | ||
| 38881 | DJNZ 38867 | Decrease B by one and loop back to 38867 | ||
| 38883 | RET | Return | ||
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