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Routines |
Prev: 59405 | Up: Map | Next: 59458 |
Used by the routine at 61882.
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59406 | LD HL,59372 | Set the instruction at 59371 to 'LD BC,31' |
59409 | LD (HL),31 | |
59411 | LD L,239 | Set the instruction at 59374 to 'LDIR' |
59413 | LD (HL),176 | |
59415 | LD B,8 | There are 8 columns to scroll on |
59417 | PUSH BC | Save the column counter |
59418 | LD B,20 | There are 20 rows to be scrolled left |
59420 | LD HL,22529 | Point HL at the attribute byte for the cell at screen coordinates (1,0) |
59423 | LD D,H | Point DE at the attribute byte for the adjacent cell on the left |
59424 | LD E,L | |
59425 | DEC E | |
59426 | PUSH BC | Save the row counter |
59427 | PUSH HL | Save the source attribute file address |
59428 | CALL 59368 | Shift this row of the screen left |
59431 | POP HL | Restore the source attribute file address to HL |
59432 | LD C,32 | Point HL at the next row down in the attribute file |
59434 | ADD HL,BC | |
59435 | POP BC | Restore the row counter to B |
59436 | DJNZ 59423 | Jump back until all 20 rows have been scrolled left |
59438 | LD HL,32766 | 32766 holds the x-coordinate of the leftmost column of the play area on screen |
59441 | INC (HL) | Increment this x-coordinate |
59442 | LD HL,4895 | L=31 (rightmost screen column), H=19 (bottom row of the screen) |
59445 | PUSH HL | Save the screen coordinates |
59446 | CALL 59148 | Print a tile at screen coordinates (31,H) |
59449 | POP HL | Restore the screen coordinates to HL |
59450 | DEC H | Have we printed every tile in the column yet? |
59451 | JP P,59445 | Jump back if not |
59454 | POP BC | Restore the column counter to B |
59455 | DJNZ 59417 | Jump back until 8 columns have been scrolled on |
59457 | RET |
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