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Routines |
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27364 | PUSH DE | Save the attribute file address temporarily | |||||||||
27365 | LD A,3 | There are 3 rows of character squares | |||||||||
27367 | LD BC,8 | There are 8 character squares in each row | |||||||||
27370 | LDIR | Copy one row of attribute bytes to the screen | |||||||||
27372 | LD C,24 | Point DE at the start of the next row down | |||||||||
27374 | EX DE,HL | ||||||||||
27375 | ADD HL,BC | ||||||||||
27376 | EX DE,HL | ||||||||||
27377 | DEC A | ||||||||||
27378 | JR NZ,27367 | Jump back to copy the remaining attributes to the screen | |||||||||
The attribute bytes have been copied to the screen. Now for the graphic bytes.
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27380 | POP DE | Restore the attribute file address to DE | |||||||||
27381 | LD A,D | Set DE to the appropriate display file address | |||||||||
27382 | SUB 80 | ||||||||||
27384 | ADD A,A | ||||||||||
27385 | ADD A,A | ||||||||||
27386 | ADD A,A | ||||||||||
27387 | LD D,A | ||||||||||
27388 | LD C,3 | There are 3 rows of character squares | |||||||||
27390 | LD A,8 | There are 8 rows of pixels per character square | |||||||||
27392 | PUSH BC | Save the character square row counter | |||||||||
27393 | PUSH DE | ||||||||||
27394 | LD C,8 | There are 8 bytes in each row of pixels | |||||||||
27396 | LDIR | Copy one row of pixels to the screen | |||||||||
27398 | POP DE | ||||||||||
27399 | INC D | Point to the display file address of the next pixel row | |||||||||
27400 | DEC A | ||||||||||
27401 | JR NZ,27393 | Jump back to fill in the remaining pixel rows for this row of character squares | |||||||||
27403 | LD A,E | Set DE to the start address of the first pixel row in the next row of character squares | |||||||||
27404 | ADD A,32 | ||||||||||
27406 | LD E,A | ||||||||||
27407 | JR C,27413 | ||||||||||
27409 | LD A,D | ||||||||||
27410 | SUB 8 | ||||||||||
27412 | LD D,A | ||||||||||
27413 | POP BC | Restore the character square row counter to C | |||||||||
27414 | DEC C | ||||||||||
27415 | JR NZ,27390 | Jump back to fill in the remaining rows of character squares | |||||||||
27417 | RET |
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