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Routines |
| Prev: F20B | Up: Map | Next: F271 |
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This clears the full screen and attributes and sets the screen border to black.
Used by the routine at main.
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Clear the pixels to zero
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| wipe_full_screen_and_attributes | F257 | LD HL,$4000 | Point HL at the start of the screen (source address) | |
| F25A | LD DE,$4001 | Point DE at the start of the screen plus a byte (destination address) | ||
| F25D | LD (HL),$00 | Set the first screen byte to zero | ||
| F25F | LD BC,$17FF | 6143 bytes | ||
| F262 | LDIR | Copy source to destination 6143 times, advancing until the screen is cleared | ||
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Clear the attributes to white over black
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| F264 | INC HL | Advance HL to the start of the attributes (source address) | ||
| F265 | INC DE | Advance DE to the start of the attributes plus a byte (destination address) | ||
| F266 | LD (HL),$07 | Set the first attribute byte to seven (white over black) | ||
| F268 | LD BC,$02FF | 767 bytes | ||
| F26B | LDIR | Copy source to destination 767 times, advancing until the screen is cleared | ||
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Set the border to black
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| F26D | XOR A | Set A to zero | ||
| F26E | OUT ($FE),A | Set the border (and speaker) | ||
| F270 | RET | Return | ||
| Prev: F20B | Up: Map | Next: F271 |