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Routines |
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59368 | XOR A | Set A=0 initially to indicate that we are copying a row of attribute bytes first | ||||||||||
59369 | PUSH HL | Save the source attribute file address | ||||||||||
59370 | PUSH DE | Save the destination attribute file address | ||||||||||
59371 | LD BC,31 | The operand of this instruction is set to 31 by the routines at 59406 and 59461, and to 32 by the routines at 59516, 59575 and 64618 | ||||||||||
59374 | LDDR | This instruction is set to LDIR by the routines at 59406, 59516, 59575 and 64618, and to LDDR by the routine at 59461; it copies the source row of attribute bytes or pixels to the destination row | ||||||||||
59376 | POP DE | Restore the destination attribute file address to DE | ||||||||||
59377 | POP HL | Restore the source attribute file address to HL | ||||||||||
59378 | AND A | Have we just copied a row of attribute bytes? | ||||||||||
59379 | JR Z,59387 | Jump if so to point DE and HL at the corresponding display file bytes | ||||||||||
59381 | INC D | Otherwise point DE and HL at the next destination and source rows of pixels | ||||||||||
59382 | INC H | |||||||||||
59383 | DEC A | Have we copied 8 rows of pixels yet? | ||||||||||
59384 | JR NZ,59369 | Jump back if not | ||||||||||
59386 | RET | |||||||||||
59387 | LD A,H | Set HL to the display file address that corresponds to the source attribute file address | ||||||||||
59388 | AND 11 | |||||||||||
59390 | ADD A,A | |||||||||||
59391 | ADD A,A | |||||||||||
59392 | ADD A,A | |||||||||||
59393 | LD H,A | |||||||||||
59394 | LD A,D | Set DE to the display file address that corresponds to the destination attribute file address | ||||||||||
59395 | AND 11 | |||||||||||
59397 | ADD A,A | |||||||||||
59398 | ADD A,A | |||||||||||
59399 | ADD A,A | |||||||||||
59400 | LD D,A | |||||||||||
59401 | LD A,8 | There are 8 rows of pixels to copy | ||||||||||
59403 | JR 59369 | Jump back to copy them |
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