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Routines |
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Used by the routine at UpdateBeams.
Clears the pixels of a beam, which is a row of bytes that all share the same pattern.
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| EraseBeam | 40229 | LD A,C | Invert the pattern. | |||||||||
| 40230 | CPL | |||||||||||
| 40231 | LD C,A | |||||||||||
| EraseBeam_Loop | 40232 | LD A,C | Fetch the inverted pattern. | |||||||||
| 40233 | AND (HL) | Clear the pixels. | ||||||||||
| 40234 | LD (HL),A | |||||||||||
| 40235 | INC L | Move on to the next byte of the row. | ||||||||||
| 40236 | DJNZ EraseBeam_Loop | Loop back to EraseBeam_Loop for each byte. | ||||||||||
| 40238 | RET | Return. | ||||||||||
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