|
Routines |
| Prev: 7514 | Up: Map | Next: 7557 |
|
||||||||||
| 7519 | PUSH DE | Save the attribute file address | ||||||||
| 751A | LD BC,$0008 | Copy the first row of attribute bytes from the graphic buffer to the screen | ||||||||
| 751D | LDIR | |||||||||
| 751F | LD C,$18 | Copy the second row of attribute bytes from the graphic buffer to the screen | ||||||||
| 7521 | EX DE,HL | |||||||||
| 7522 | ADD HL,BC | |||||||||
| 7523 | EX DE,HL | |||||||||
| 7524 | LD C,$08 | |||||||||
| 7526 | LDIR | |||||||||
| 7528 | LD C,$18 | Copy the third row of attribute bytes from the graphic buffer to the screen | ||||||||
| 752A | EX DE,HL | |||||||||
| 752B | ADD HL,BC | |||||||||
| 752C | EX DE,HL | |||||||||
| 752D | LD C,$08 | |||||||||
| 752F | LDIR | |||||||||
|
The attribute bytes have been copied to the screen. Now for the graphic bytes. This entry point is used by the routine at 75CC.
|
||||||||||
| 7531 | POP DE | Restore the attribute file address to DE | ||||||||
| 7532 | LD A,D | Set DE to the corresponding display file address | ||||||||
| 7533 | SUB $50 | |||||||||
| 7535 | ADD A,A | |||||||||
| 7536 | ADD A,A | |||||||||
| 7537 | ADD A,A | |||||||||
| 7538 | LD D,A | |||||||||
| 7539 | LD C,$03 | There are three rows of UDGs to copy to the screen | ||||||||
| 753B | LD A,$08 | There are 8 pixel lines per row of UDGs | ||||||||
| 753D | PUSH BC | Save C (the row counter) | ||||||||
| 753E | PUSH DE | Copy a row of 8 UDGs from the graphic buffer to the screen | ||||||||
| 753F | LD C,$08 | |||||||||
| 7541 | LDIR | |||||||||
| 7543 | POP DE | |||||||||
| 7544 | INC D | |||||||||
| 7545 | DEC A | |||||||||
| 7546 | JR NZ,$753E | |||||||||
| 7548 | LD A,E | Set DE to the display file address for the next row | ||||||||
| 7549 | ADD A,$20 | |||||||||
| 754B | LD E,A | |||||||||
| 754C | JR C,$7552 | |||||||||
| 754E | LD A,D | |||||||||
| 754F | SUB $08 | |||||||||
| 7551 | LD D,A | |||||||||
| 7552 | POP BC | Restore the row counter to C | ||||||||
| 7553 | DEC C | Next row | ||||||||
| 7554 | JR NZ,$753B | Jump back until all three rows of UDGs have been copied | ||||||||
| 7556 | RET | |||||||||
| Prev: 7514 | Up: Map | Next: 7557 |