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Routines |
Prev: 59458 | Up: Map | Next: 59513 |
Used by the routine at 61838.
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59461 | LD HL,59372 | Set the instruction at 59371 to 'LD BC,31' |
59464 | LD (HL),31 | |
59466 | LD L,239 | Set the instruction at 59374 to 'LDDR' |
59468 | LD (HL),184 | |
59470 | LD B,8 | There are 8 columns to scroll on |
59472 | PUSH BC | Save the column counter |
59473 | LD B,20 | There are 20 rows to be scrolled right |
59475 | LD HL,22558 | Point HL at the attribute byte for the cell at screen coordinates (0,0) |
59478 | LD D,H | Point DE at the attribute byte for the adjacent cell on the right |
59479 | LD E,L | |
59480 | INC E | |
59481 | PUSH BC | Save the row counter |
59482 | PUSH HL | Save the source attribute file address |
59483 | CALL 59368 | Shift this row of the screen right |
59486 | POP HL | Restore the source attribute file address to HL |
59487 | LD C,32 | Point HL at the next row down in the attribute file |
59489 | ADD HL,BC | |
59490 | POP BC | Restore the row counter to B |
59491 | DJNZ 59478 | Jump back until all 20 rows have been scrolled right |
59493 | LD HL,32766 | 32766 holds the x-coordinate of the leftmost column of the play area on screen |
59496 | DEC (HL) | Decrement this x-coordinate |
59497 | LD HL,4864 | L=0 (leftmost screen column), H=19 (bottom row of the screen) |
59500 | PUSH HL | Save the screen coordinates |
59501 | CALL 59148 | Print a tile at screen coordinates (0,H) |
59504 | POP HL | Restore the screen coordinates to HL |
59505 | DEC H | Have we printed every tile in the column yet? |
59506 | JP P,59500 | Jump back if not |
59509 | POP BC | Restore the column counter to B |
59510 | DJNZ 59472 | Jump back until 8 columns have been scrolled on |
59512 | RET |
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