processor 6502 include "vcs.h" include "macro.h" include "xmacro.h" seg.u Variables org $80 ; 16-bit wavetable offset Cycle0Lo byte Cycle1Lo byte Cycle2Lo byte Cycle3Lo byte Cycle0Hi byte Cycle1Hi byte Cycle2Hi byte Cycle3Hi byte ; 16-bit wavetable delta Delta0Lo byte Delta1Lo byte Delta2Lo byte Delta3Lo byte Delta0Hi byte Delta1Hi byte Delta2Hi byte Delta3Hi byte ; 8-bit wavetable offset (volume) WaveOfs0 byte WaveOfs1 byte WaveOfs2 byte WaveOfs3 byte SongPtr word ; ptr to next song byte DurationTimer byte ; duration until next song byte CurChannel byte ; next channel to write ;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;; seg Code org $f000 ; Macro that decrements volume for a channel MAC DECVOLUME lda WaveOfs0+{1} sec beq .ChannelOff sbc #$20 .ChannelOff sta WaveOfs0+{1} ENDM Start CLEAN_START lda #$FF sta COLUPF sta ENABL jsr ResetTrack NextFrame DECVOLUME 0 jsr Pulse jsr PlayFrame DECVOLUME 1 jsr Pulse jsr PlayFrame DECVOLUME 2 jsr Pulse jsr PlayFrame DECVOLUME 3 jsr Pulse jsr PlayFrame jmp NextFrame ; Play a frame's worth of samples PlayFrame TIMER_SETUP 212 TimerLoop1 jsr NextSamples lda INTIM cmp #3 bcs TimerLoop1 rts ;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;; ; Macro that mixes two software voices ; and sets the volume for one TIA audio channel. ; Usage: NEXTSAMPLEPAIR {audiochannel} {voice1} {voice2} MAC NEXTSAMPLEPAIR ; Get first channel phase, put in X lda Cycle0Lo+{2} clc adc Delta0Lo+{2} sta Cycle0Lo+{2} lda Cycle0Hi+{2} adc Delta0Hi+{2} sta Cycle0Hi+{2} and #$1F clc adc WaveOfs0+{2} tax ; Get second channel phase, put in Y lda Cycle0Lo+{3} clc adc Delta0Lo+{3} sta Cycle0Lo+{3} lda Cycle0Hi+{3} adc Delta0Hi+{3} sta Cycle0Hi+{3} and #$1F clc adc WaveOfs0+{3} tay ; Lookup wavetable entry and sum lda Wavetable,y clc adc Wavetable,x ; Divide by 2 and store to volume register lsr ; sta COLUBK sta AUDV0+{1} ENDM NextSamples NEXTSAMPLEPAIR 0,0,1 ; mix voices 0 and 1 NEXTSAMPLEPAIR 1,2,3 ; mix voices 2 and 3 rts ; Play a note ; X = channel (0,1) ; Y = note index (0-63) PlayNote tya asl tay lda NoteDeltas,y sta Delta0Lo,x lda NoteDeltas+1,y sta Delta0Hi,x lda #$e0 sta WaveOfs0,x rts ; Reset to start of song ResetTrack lda #NOTEZ sta SongPtr+1 rts ; Called every frame ; Decrement next-note timer, fetch next note Pulse lda DurationTimer beq NextData dec DurationTimer rts ; Timer ran out, so fetch next note NextData jsr NextSamples ldx #0 lda (SongPtr,x) ; get next song byte bmi LoadDuration ; < $80, so play next note ldx CurChannel ; load next channel # tay jsr PlayNote ; play note inx txa and #3 sta CurChannel ; inc to next channel jmp IncDataPtr ; >= $80 so load next duration LoadDuration cmp #$ff beq ResetTrack ; $ff = end of song and #$7f asl sta DurationTimer ; store duration * 2 IncDataPtr ; increment song pointer inc SongPtr bne NoIncHi inc SongPtr+1 NoIncHi rts ; 32-byte wavetable align $100 Wavetable hex 00000000 00000000 00000000 00000000 hex 00000000 00000000 00000000 00000000 hex 04040404 04040404 04040404 04040404 hex 04040404 04040404 00000000 00000000 hex 06060606 06060606 06060606 06060606 hex 06060606 06060606 00000000 00000000 hex 08080808 08080808 08080808 08080808 hex 08080808 08080808 00000000 00000000 hex 0b0b0b0b 0b0b0b0b 0b0b0b0b 0b0b0b0b hex 0b0b0b0b 0b0b0b0b 0b0b0b0b 00000000 hex 0d0d0d0d 0d0d0d0d 0d0d0d0d 0d0d0d0d hex 0d0d0d0d 0d0d0d0d 00000000 00000000 hex 0f0f0f0f 0f0f0f0f 0f0f0f0f 0f0f0f0f hex 0f0f0f0f 00000000 00000000 00000000 hex 0f0f0f0f 0f0f0f0f 0f0f0f0f 0f0f0f0f hex 00000000 00000000 00000000 00000000 ; hex 00010203 04050607 08090a0b 0c0d0e0f ; hex 0f0e0d0c 0b0a0908 07060504 03020100 ; Table of note periods NoteDeltas word 17, 18, 19, 20, 22, 23, 24, 26, 27, 29, 31, 32, word 34, 36, 39, 41, 43, 46, 49, 51, 54, 58, 61, 65, word 69, 73, 77, 82, 86, 92, 97, 103, 109, 115, 122, 130, word 137, 145, 154, 163, 173, 183, 194, 206, 218, 231, 245, 259, word 274, 291, 308, 326, 346, 366, 388, 411, 436, 462, 489, 518, word 549, 582, 616, 653, 692, 733, 776, 823, 871, 923, 978, 1036, word 1098, 1163, 1232, 1306, 1383, 1466, 1553, 1645, 1743, 1847, 1956, 2073, word 2196, 2327, 2465, 2611, 2767, 2931, 3106, 3290, 3486, 3693, 3913, 4145, word 4392, 4653, 4930, 5223, 5533, 5862, 6211, 6580, 6972, 7386, 7825, 8291, word 8784, 9306, 9859, 10446, 11067, 11725, 12422, 13161, 13943, 14772, 15651, 16582, word 17568, 18612, 19719, 20891, 22134, 23450, 24844, 26322, NOTEZ hex 358a378a333f8a303c943e328a3a2e94 hex 35298a372b8a33278a30249432268a2e hex 2294291d8a2b1f8a271b8a2418941a26 hex 8a18248a17238a1622a83a35322e9429 hex 26228a2a8a2b1b8a338a221f278a2b8a hex 332216942b2725228a338a2014942724 hex 941f138a3f37338a383527228a39368a hex 3a37168a3f37338a353822278a3a378a hex 168a3e35328a38352622943f33371b94 hex 1f22279427221f942926228a2a8a2b1b hex 8a338a1f22278a2b8a332216942b2725 hex 228a338a2014942427941f13943c3330 hex 1e8a3a332e8a39332d1d8a3c308a3f33 hex 1d248a378a1d8a358a3f3327218a3c30 hex 8a353826229422169424189429261a8a hex 2a8a2b1b8a338a27221f8a2b8a331622 hex 942b2725228a338a201494272494131f hex 8a3f33378a383527228a39368a373a16 hex 8a3f37338a383527228a3a378a168a3e hex 35328a38352026943f37331b9427221f hex 942b2722943f338a358a37271b8a3f33 hex 8a352b22278a378a25198a3f338a352b hex 27228a3f338a3724188a3f338a352c27 hex 248a378a23178a3f338a352c27238a3f hex 338a3a3722168a3f37338a38352b278a hex 3a378a168a3e32358a35382622943f33 hex 371b9422169424189429261a8a2a8a2b hex 1b8a338a27221f8a2b8a332216942b25 hex 22278a338a2014942724941f138a3f37 hex 338a353827228a39368a3a37168a3f37 hex 338a383527228a3a378a168a3e35328a hex 353820229437333f1b9427221f942722 hex 1f942926228a2a8a2b1b8a338a221f27 hex 8a2b8a332216942b2725228a338a2014 hex 942724941f13943c33301e8a3a332e8a hex 2d33391d8a3c308a3f3327248a378a1d hex 8a358a333f27248a3c308a3835262294 hex 22169424189429261a8a2a8a2b1b8a33 hex 8a22271f8a2b8a332216942b2725228a hex 338a2014942427941f138a3f37338a38 hex 3527228a36398a3a37168a3f37338a38 hex 3527228a373a8a168a3e35328a383522 hex 209433373f1b9427221f9422272b943f hex 338a358a37271b8a3f338a352b27228a hex 378a25198a3f338a352b22278a3f338a hex 3724188a333f8a352c27248a378a2317 hex 8a3f338a352c27238a3f338a3a372216 hex 8a3f37338a38352b278a373a8a168a3e hex 35328a383522269433373f2794221694 hex 1b0f8a372b338a382c358a39362d8a3a hex 372e0f943c37302b8a3a2e378a168a37 hex 332b8a2c38352b8a39362d8a3a372e1b hex 943c3730278a2e373a8a168a378a3327 hex 2b228a2e8a30148a328a332c27248a35 hex 8a37208a358a332c27238a358a2e1f8a hex 378a382b27228a3a8a3c168a3a8a3722 hex 2b278a388a3a372e1b943c30372b8a3a hex 372e8a168a37332b8a382c35228a3936 hex 2d8a3a372e1b943c37302b8a2e373a8a hex 1f8a3a8a3c1e8a3d8a3e3a351d8a3e35 hex 3a8a2229268a3e33398a1d8a3c8a3933 hex 29278a358a3a322926942014941f138a hex 372b338a38352c1d8a39362d8a2e3a37 hex 1b943c3730228a3a372e8a168a332b37 hex 8a38352c2b8a39362d8a3a372e1b9430 hex 373c2b8a3a2e378a168a378a332b2722 hex 8a2e8a30148a328a332c27248a358a37 hex 208a358a33232c278a358a331f942b22 hex 27941b8a2e8a2d2b27258a2e8a332c27 hex 2494302c27248a338a21242a278a308a hex 332a27248a308a2e2b27228a338a372b hex 22278a3a8a2b27228a378a332b27228a hex 2e8a302d1d2794332d241d94372c2622 hex 8a352c8a26228a332b8a271b94221694 hex 1f138a3f378a381d118a398a3a372e1b hex 943c3037228a3a372e8a168a37332b8a hex 382c352b8a39362d8a3a372e1b943c37 hex 302b8a2e373a8a168a378a332b27228a hex 2e8a30148a328a332c27248a358a3720 hex 8a358a3323272c8a358a2e1f8a378a38 hex 272b228a3a8a3c168a3a8a372b27228a hex 388a3a372e1b943c30372b8a3a372e8a hex 168a37332b8a382c352b8a39362d8a3a hex 372e1b943c3730228a2e373a8a1f8a3a hex 8a3c1e8a3d8a3e3a351d8a3e353a8a29 hex 26228a3e33398a1d8a3c8a393327248a hex 358a3a322926942014941f138a372b33 hex 8a38352c118a39362d8a2e3a371b943c hex 37302b8a3a372e8a168a332b378a3835 hex 2c2b8a39362d8a3a372e1b94303c372b hex 8a372e3a8a168a378a332b27228a2e8a hex 30148a328a3327242c8a358a37208a35 hex 8a332c27238a358a331f942b2722941b hex 8a2e8a2d2b27258a2e8a332c27249430 hex 2c20278a338a2a2724218a308a332a27 hex 248a308a2e2b22278a338a372b27228a hex 3a8a2b27228a378a332b22278a2e8a30 hex 2d271d94332d241d94372c26228a352c hex 8a26228a332b8a271b942216941b0f94 hex 298a2a8a2b1b8a338a271f228a2b8a33 hex 2216942b2725228a338a201494272494 hex 1f138a3f37338a383527228a39368a3a hex 37168a3f37338a383527228a3a378a16 hex 8a3e35328a38352220943f37331b9427 hex 221f94221f27942926228a2a8a2b1b8a hex 338a27221f8a2b8a332216942b272225 hex 8a338a2014942724941f1394333c301e hex 8a3a332e8a39332d1d8a3c308a3f3327 hex 248a378a1d8a358a3f3327248a3c308a hex 353826229422169424189429261a8a2a hex 8a2b1b8a338a1f22278a2b8a33221694 hex 2b2725228a338a2014942427941f138a hex 3f37338a383527228a39368a373a168a hex 3f33378a353827228a3a378a168a3e35 hex 328a38352622943f37331b9427221f94 hex 222b27943f338a358a37271b8a3f338a hex 352b27228a378a25198a333f8a352722 hex 2b8a3f338a3724188a3f338a352c2724 hex 8a378a23178a3f338a3523272c8a3f33 hex 8a3a3716228a33373f8a38352b278a3a hex 378a168a32353e8a38352622943f3733 hex 27942216943f37331ba8383c148a3b8a hex 3c382427941b943f3c382c94383d1994 hex 312c29258a308a31208a338a352c2529 hex 943835118a378a38352c299418943c38 hex 352494353a3d16942e25298a2d8a2e1d hex 8a308a3129258a3a8a352519943a2529 hex 8a358a22168a3a8a3523179433241894 hex 24272c94381d942c292494371f8a3b8a hex 3e26292b8a8a238a8a3e2b29268a3f8a hex 3c2b2724a83d22272b941b943c38148a hex 3b8a383c2c27941b943f3c382c943d38 hex 1994312c25298a308a31208a338a352c hex 2925943835118a378a38352c24941894 hex 353c382c943d3a3516942e29258a2d8a hex 2e1d8a308a3129258a3a8a352519943a hex 29258a358a16228a3a8a352317943324 hex 188a20148a1f138a111d8a38322f1c9e hex 388a3c33301b8a3f338a2c27248a3a31 hex 8a271b8a338a35311b0f8a378a383020 hex 1494328a338a358a378a388a3a8a3c38 hex 148a3b8a383c2c27941b943f3c382c94 hex 3d381994312c29258a308a31208a338a hex 35292c25943835118a378a38352c2994 hex 18943c35382c94353d3a16942e29258a hex 2d8a2e1d8a308a3129258a3a8a352519 hex 943a29258a358a22168a3a8a35231794 hex 332418942c272494381d942c29249437 hex 1f8a3b8a3e262b298a8a238a8a3e2b29 hex 268a3f8a3c2b2724a83d2b2722941b94 hex 3c38148a3b8a383c242c941b943f3c38 hex 2c943d381994312c29258a308a31208a hex 338a352c2925943538118a378a38352c hex 299418943c383524943d3a3516942e25 hex 298a2d8a2e1d8a308a3129258a3a8a35 hex 2519943a29258a358a22168a3a8a3523 hex 17943324188a20148a1f138a1d118a38 hex 322f1c9e388a30333c1b8a3f338a2c27 hex 248a3a318a271b8a338a35311b0f8a37 hex 8a30382014a83f3c3814a83320272494 hex 302c27248a338a2a2724218a308a332a hex 21248a308a2e2b27228a338a3722272b hex 8a3a8a2b27228a378a332b27228a2e8a hex 302d271d94332d241d94372c26228a35 hex 2c8a26228a332b8a271ba833373a3fa8 hex 2c2914942b2820248a2c298a188a2b28 hex 8a292c242094148a308a2c3524208a30 hex 8a33188a358a3324208a308a2e2b1b94 hex 2d2a27228a2e2b8a168a2d2a8a2e2b1f hex 27941b8a338a372e27228a338a35168a hex 378a351f22278a338a35321694343126 hex 228a35328a1a8a34318a323526229416 hex 8a388a3c3222268a388a3a1d8a3c8a3a hex 2622208a388a3f3327218a3f338a3f33 hex 2721a83c332721943a331f27942e2b8a hex 2e2b8a2e2b942b2e942c2914942b2824 hex 208a2c298a188a2b288a2c2924209414 hex 8a308a352c20248a308a33188a358a33 hex 24208a308a2e2b1b942a2d27228a2e2b hex 8a168a2d2a8a2e2b1f27941b8a338a37 hex 2e271f8a338a35168a378a3527221f8a hex 338a3020148a2f8a301d118a3a308a1f hex 138a38308a20148a33308a372e22168a hex 368a37222b278a3c8a2a27218a3f8a3a hex 2b27228a378a332d182494332d1d1194 hex 372c32228a35322c8a261a8a332e2b8a hex 271b942b2e8a2e2b8a2e2b942e2b942c hex 1b942216943f3a3733ff ; Epilogue org $fffc .word Start .word Start