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Routines |
| Prev: 64456 | Up: Map | Next: 64582 |
| 64548 | LD B,96 | Load B with 96 (number of times to repeat routine) | ||
| 64550 | LD DE,576 | Load DE with 576 (number of bytes to modify - i.e. bottom 18 rows) | ||
| 64553 | LD HL,22720 | Point HL at start of 7th row in attribute file | ||
| 64556 | LD A,(HL) | Load attribute byte into A | ||
| 64557 | AND 248 | Clear three lowest bits (i.e. INK colour) preserving only PAPER, BRIGHT and FLASH bits | ||
| 64559 | LD C,A | Place modified value into C | ||
| 64560 | LD A,(HL) | Get original attribute from screen again | ||
| 64561 | INC A | Increase by one | ||
| 64562 | AND 7 | Clear all bits except the lowest three (i.e. INK colour) | ||
| 64564 | OUT (254),A | Set border colour to A | ||
| 64566 | OR C | Combine other bits back in | ||
| 64567 | OUT (254),A | Update border / speaker state | ||
| 64569 | LD (HL),A | Load modified value back into attribute file | ||
| 64570 | INC HL | Move to next byte in attribute file | ||
| 64571 | DEC DE | Reduce DE (reducing number of attribute bytes left to modify) | ||
| 64572 | LD A,D | If DE is not zero (i.e. there are more attribute bytes to modify)... | ||
| 64573 | OR E | ... | ||
| 64574 | JR NZ,64556 | ...then loop back to 64556 | ||
| 64576 | DJNZ 64550 | Loop back for another pass | ||
| 64578 | XOR A | Set A to zero | ||
| 64579 | OUT (254),A | Reset border to black and reset speaker state | ||
| 64581 | RET | Return | ||
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