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Routines |
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Used by the routine at DrawingSetup.
Moves the screen address up one character row.
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| Drawing_StepUpOneRow | 33013 | PUSH AF | One screen row is 32 bytes. | |
| 33014 | PUSH DE | |||
| 33015 | LD DE,32 | |||
| 33018 | AND A | Clear carry before stepping the screen address back one row. | ||
| 33019 | SBC HL,DE | See how far the pointer is past 0032. | ||
| 33021 | LD A,H | Jump to Drawing_StepUpOneRow_RestoreTheRowStep if the screen address is not in row 87. | ||
| 33022 | CP 87 | |||
| 33024 | JR NZ,Drawing_StepUpOneRow_RestoreTheRowStep | |||
| 33026 | ADD HL,DE | Step down one attribute row. | ||
| Drawing_StepUpOneRow_RestoreTheRowStep | 33027 | POP DE | Restore DE and AF from the stack. | |
| 33028 | POP AF | |||
| 33029 | RET | Return. | ||
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View the equivalent code in;
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