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executable file 134 lines (116 sloc) 3.24 KB
.include "apple2.inc"
.include "zeropage.inc"
.import popa
.export _note
.export _pause
.DATA
;NB nop loops of each note, lasting hal a period
Half_Periods: .byte 251, 237, 224, 211, 199, 188, 177, 167, 158
.byte 149, 140, 132, 125, 118, 111, 105, 99, 93, 88, 83, 78
.byte 74, 69, 65, 62, 58, 55, 52, 49, 46, 43, 41, 38
;NB duration loop for each note to last for 1 second
Durations: .word 311, 330, 349, 370, 392, 415, 440, 466, 494
.word 523, 554, 587, 622, 659, 698, 740, 784, 831, 880, 932, 988
.word 1047, 1109, 1175, 1245, 1319, 1397, 1480, 1568, 1661, 1760, 1865, 1976
;Inner and Outer loop of silence to last for 1 second
Silence_Inner: .byte 125
Silence_Outer: .word 622
.ALIGN 256
.CODE
; ******************
; \param idx_note : index of the note to play, used to fetch values in Half_Periods and Durations tables
;void __fastcall__ note( uint8_t nb_shift_duration, uint8_t idx_note )
_note:
;aliases
half_period := tmp1
duration_lo := tmp2
duration_hi := tmp3
;processing parameters
TAX ; idx_note in X
LDA Half_Periods, X
STA half_period
TXA
ASL ;Durations are on 16 bits
TAX
LDA Durations, X
STA duration_lo
LDA Durations+1, X
STA duration_hi
JSR popa ; nb_shift_duration in A
TAY
BEQ end_shift
loop_shift: ;shifting the duration
LSR duration_hi
ROR duration_lo
DEY
BNE loop_shift
end_shift:
;Init loop duration
CLC
LDY duration_lo
INC duration_hi
;Starting to vibe ;)
;These loop should fit in one page to respect the timings
loop_half_period:
LDA $C030 ;4 cycles //SPEAKER
LDX half_period ;3 cycles
loop_nops:
NOP ;2 cycles
NOP ;2 cycles
NOP ;2 cycles
NOP ;2 cycles
DEX ;2 cycles
BNE loop_nops ;3 cycles
;Testing duration loop
DEY ;2 cycles
BNE loop_half_period ;3 cycles
DEC duration_hi ;5 cycles
BNE loop_half_period ;3 cycles
end:
RTS
.ALIGN 256
; ******************
;void __fastcall__ pause( uint8_t nb_shift_duration )
_pause:
;DEBUG:
; CLC
; BCC DEBUG
; ; ++++++ DEBUG
;aliases
pause_lo := tmp2
pause_hi := tmp3
TAY ; duration shift in Y
INY
LDA Silence_Outer
STA pause_lo
LDA Silence_Outer+1
STA pause_hi
DEY
BEQ end_shift_silence
loop_shift_silence: ;shifting the duration
LSR pause_hi
ROR pause_lo
DEY
BNE loop_shift_silence
end_shift_silence:
;Init loop duration
CLC
LDY pause_lo
INC pause_hi
;Starting to be mute
;These loop should fit in one page to respect the timings
loop_silence:
LDX Silence_Inner ;4 cycles
loop_nops_silence:
NOP ;2 cycles
NOP ;2 cycles
NOP ;2 cycles
NOP ;2 cycles
DEX ;2 cycles
BNE loop_nops_silence ;3 cycles
;Testing duration loop
DEY ;2 cycles
BNE loop_silence ;3 cycles
DEC pause_hi ;5 cycles
BNE loop_silence ;3 cycles
RTS