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Routines |
| Prev: AFC8 | Up: Map | Next: B001 |
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Right-shifts every pixel in the display file ($4000–$57FF) 8 times,
creating a wipe-to-black effect. Then fills the attribute file with
the fade colour stored in var_fade_attr.
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| fade_out | AFD1 | LD A,$08 | A = 8 (outer loop count — 8 shift passes) | |
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Per-pass: shift all 24×32 pixels right by 1 bit
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| fade_out_0 | AFD3 | LD HL,$4000 | HL = $4000 (start of display file) | |
| AFD6 | LD C,$18 | C = 24 (row count) | ||
| fade_out_1 | AFD8 | LD B,$00 | B = 0 (256 bytes per row) | |
| fade_out_2 | AFDA | SRL (HL) | SRL (HL) + INC HL (shift then advance pointer) | |
| AFDC | INC HL | LD A,$23 (unused byte — artifact of encoding) | ||
| AFDD | DJNZ fade_out_2 | DJNZ — repeat for all 256 bytes in row | ||
| AFDF | DEC C | DEC C | ||
| AFE0 | JR NZ,fade_out_1 | JR NZ — next row | ||
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Inter-pass delay
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| AFE2 | LD B,$00 | B = 0 (256 iterations) | ||
| fade_out_3 | AFE4 | DEC B | DJNZ self — inner spin (+ padding byte $FD) | |
| AFE5 | JR NZ,fade_out_3 | |||
| AFE7 | LD C,$00 | C = 0 (256 iterations) | ||
| fade_out_4 | AFE9 | DEC C | DJNZ self — outer spin (+ padding byte $FD) | |
| AFEA | JR NZ,fade_out_4 | |||
| AFEC | DEC A | DEC A | ||
| AFED | JR NZ,fade_out_0 | JR NZ — repeat all 8 passes | ||
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Fill attribute file with fade colour
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| AFEF | LD HL,$5800 | HL = $5800 (attribute file start) | ||
| AFF2 | LD A,($C34F) | A = fade colour (var_fade_attr) | ||
| AFF5 | LD C,$18 | C = 24 (row count) | ||
| fade_out_5 | AFF7 | LD B,$20 | B = 32 (columns per row) | |
| fade_out_6 | AFF9 | LD (HL),A | Write A to (HL) | |
| AFFA | INC HL | INC HL | ||
| AFFB | DJNZ fade_out_6 | DJNZ — fill 32 columns | ||
| AFFD | DEC C | DEC C | ||
| AFFE | JR NZ,fade_out_5 | JR NZ — next row | ||
| B000 | RET | |||
| Prev: AFC8 | Up: Map | Next: B001 |