.global __vectors SREG = 0x3F CCP = 0x3C SMCR = 0x3A CLKPSR = 0x36 TCCR0A = 0x2E TCCR0B = 0x2D TCCR0C = 0x2C TIMSK0 = 0x2B TIFR0 = 0x2A OCR0AL = 0x26 PUEB = 0x03 PORTB = 0x02 DDRB = 0x01 PINB = 0x00 LEADSIZE = 174 LEADINIT1 = 1601 LEADINIT2 = 3571 .section .bss .comm int_ctr, 1 .comm i, 3 .comm lead1, 4 .comm lead2, 4 .comm lead3, 4 .comm bassosc, 2 .comm bassflange, 2 .comm arposc, 2 .comm boost, 1 ; leaves 9 bytes for stack .section .text __vectors: NULL: clr r16 ldi r17, 0xD8 out PUEB, r16 rjmp main_cont .type __vector_4, @function __vector_4: push r16 push r24 in r16, SREG lds r24,int_ctr subi r24,lo8(-(1)) andi r24,lo8(3) sts int_ctr,r24 out SREG,r16 pop r24 pop r16 reti .size __vector_4, .-__vector_4 main_cont: clr r31 ldi r30, 0x40 clear_sram: st Z+, r16 sbrs r30, 5 rjmp clear_sram ldi r18, 0;LEADSIZE sts lead1, r18 sts lead2, r18 sts lead3, r18 ; ldi r18, hi8(LEADINIT1) ; sts leadosc2, r18 ; ldi r18, lo8(LEADINIT1) ; sts leadosc2 + 1, r18 ; ldi r18, hi8(LEADINIT2) ; sts leadosc3, r18 ; ldi r18, lo8(LEADINIT2) ; sts leadosc3 + 1, r18 out CCP, r17 out CLKPSR, r16 ldi r17, 5 out DDRB, r17 ldi r17, 0x81 out TCCR0A, r17 ldi r17, 0x09 out TCCR0B, r17 ldi r17, 1 out SMCR, r17 out TIMSK0, r17 sei out TIFR0, r17 mainloop: sleep clr r16 lds r17, int_ctr tst r17 brne mainloop sbi PORTB, 2 lds r17, i lds r18, i+1 lds r19, i+2 subi r19, 0xff sbci r18, 0xff sbci r17, 0xff ; if ((i >> 13) == 76) i = 16 << 13; mov r20, r18 rol r20 mov r20, r17 rol r20 subi r20, 0x13 brne norestart ldi r17, 2 clr r18 norestart: sts i, r17 sts i+1, r18 sts i+2, r19 ; ==== BASS ==== ; bassptr(r20) = (i >> 13) & 0xF mov r20, r17 ror r20 mov r20, r18 ror r20 swap r20 andi r20, 0xF ; if (i >> 19) & 1: bassptr |= 0x10 sbrc r17, 3 ori r20, 0x10 ; note = notes[bassline[bassptr]] ldi r31, hi8(bassline+0x4000) ldi r30, lo8(bassline) add r30, r20 ld r20, Z ldi r30, lo8(notes) add r30, r20 ld r21, Z+ ld r20, Z ; if (bassbeat[(i >> 10) & 7]): note <<= 1 mov r22, r18 lsr r22 lsr r22 andi r22, 7 ldi r30, lo8(bassbeat) add r30, r22 ld r22, Z tst r22 ; assuming this resets C breq nobassbeat rol r21 rol r20 nobassbeat: ; bassosc += note, ret = (bassosc >> 8) & 0x7F lds r22, bassosc lds r23, bassosc + 1 add r23, r21 adc r22, r20 sts bassosc, r22 sts bassosc + 1, r23 mov r24, r22 andi r24, 0x7F ; bassflange += note + 1, ret += (bassflange >> 8) & 0x7F lds r22, bassflange lds r23, bassflange + 1 inc r21 add r23, r21 adc r22, r20 sts bassflange, r22 sts bassflange + 1, r23 andi r22, 0x7F add r24, r22 ; if ((i >> 6) & 0xF) == 0xF: sample += (bass >> 2) lsr r24 lsr r24 mov r20, r18 andi r20, 3 subi r20, 3 brne addbass mov r20, r19 andi r20, 0xC0 subi r20, 0xC0 breq noaddbass addbass: add r16, r24 noaddbass: ; ==== ARPEGGIO ==== ; arpptr(r30) = arpseq1[arpseq2[i >> 16]][(i >> 14) & 3] mov r30, r17 subi r30, lo8(NULL-arpseq2) ld r30, Z lsl r30 lsl r30 mov r20, r18 swap r20 lsr r20 lsr r20 andi r20, 3 or r30, r20 subi r30, lo8(NULL-arpseq1) ld r30, Z ; if (!(i & (1 << 13))): arpptr >>= 14 sbrs r18, 5 swap r30 ; arpptr = arpeggio[arpptr & 0xF][(i >> 8) & 1] andi r30, 0xF lsl r30 mov r20, r18 andi r20, 1 or r30, r20 subi r30, lo8(NULL-arpeggio) ld r30, Z ; if (!(i & 0x80)): arpptr >>= 14 sbrs r19, 7 swap r30 ; note = arpnotes[arpptr & 0xF] andi r30, 0xF lsl r30 subi r30, lo8(NULL-arpnotes) ld r21, Z+ ld r20, Z ; arp_osc += note lds r22, arposc lds r23, arposc + 1 add r23, r21 adc r22, r20 sts arposc, r22 ; keep r22 for later! sts arposc + 1, r23 ; if (!(i >> 17)): break arp mov r20, r17 lsr r20 breq noarp ; r20 = arptiming[(i >> 12) & 3] mov r30, r18 swap r30 andi r30, 3 subi r30, lo8(NULL-arptiming) ld r20, Z ; if (!((r20 << ((i >> 9) & 7)) & 0x80)): break arp mov r21, r18 lsr r21 andi r21, 7 breq arptiming_noshift arptiming_shift: lsl r20 subi r21, 1 brne arptiming_shift arptiming_noshift: sbrs r20, 7 rjmp noarp ; if (arp_osc & (1 << 12)): sample += 35; sbrc r22, 4 subi r16, -35 noarp: ; ==== LEAD === clr r29 ldi r28, lead1 ldi r24, 0 ldi r25, ~1 rcall lead_voice mov r16, r23 ;ldi r28, lead2 ;ldi r24, 4 ;ldi r25, ~2 ;rcall lead_voice ;lsr r23 ;lsr r23 ;add r16, r23 ;lsr r23 ;add r16, r23 ;ldi r28, lead3 ;ldi r24, 8 ;ldi r25, ~4 ;rcall lead_voice ;lsr r23 ;lsr r23 ;add r16, r23 out OCR0AL, r16 cbi PORTB, 2 rjmp mainloop ; input: ; dataset pointer in Y ; inverted boost mask in r25 ; voice delay (4 * voice_nr) in r24 ; returns sample in r23 skiplead_top: clr r23 ret lead_voice: ld r23, Y+ ; r23 = leadptr cpi r23, LEADSIZE brne noleadsetup cpi r17, 4 brne skiplead_top cp r18, r24 ; r24 no longer needed now! brne skiplead_top tst r19 brne skiplead_top dec r28 ldi r23, -1 st Y+, r23 ldi r20, 1 st Y, r20 noleadsetup: lds r26, boost ; r26 = boost ld r27, Y ; r27 = leadtimer ; if (0 == (i & 0xFF)): clear boost tst r19 brne checkleadtimer and r26, r25 sts boost, r26 ; if (0 == i & 0x1FF): leadtimer-- sbrc r18, 0 rjmp checkleadtimer dec r27 st Y, r27 checkleadtimer: ; if (0 == leadtimer): leadptr++ tst r27 brne getleaddata ; leadptr++ dec r28 inc r23 st Y+, r23 getleaddata: ; leadptr(4..7) = leadseq[leadptr >> 4]; mov r30, r23 andi r23, 0xF swap r30 andi r30, 0xF subi r30, lo8(NULL-leadseq) ld r30, Z swap r30 or r30, r23 ; data = leaddata[leadptr] subi r30, lo8(NULL-leaddata) ld r24, Z ; r24 = data! ; if (0 == leadtimer) { neg r25 tst r27 brne noleadupdate ; leadtimer = leadtimes[data >> 5] mov r30, r24 swap r30 lsr r30 andi r30, 7 subi r30, lo8(NULL-leadtimes) ld r27, Z st Y, r27 ; boosts |= boostmask or r26, r25 sts boost, r26 noleadupdate: ; data &= 0x1F andi r24, 0x1F ; note = notes[data] ldi r30, lo8(notes) lsl r24 add r30, r24 ld r21, Z+ ld r20, Z ; leadosc += note inc r28 ld r22, Y+ ld r23, Y add r23, r21 adc r22, r20 st Y, r23 st -Y, r22 ; sample = ((lead_osc >> 7) & 0x3F) + ((lead_osc >> 7) & 0x1F) rol r23 rol r22 andi r22, 0x3F mov r23, r22 andi r22, 0x1F add r23, r22 ; r23 = final boosted sample! ; if (!(boost & boostmask)): take three quarters and r26, r25 brne noreduce lsr r23 mov r22, r23 lsr r23 add r23, r22 noreduce: ; if (data == 0) return 0; tst r24 breq skiplead ret skiplead: clr r23 ret .org 0x300 notes: .word -1, 134, 159, 179, 201 arpnotes: .word 213, 239, 268, 301, 319, 358, 401, 425, 451, 477, 536, 601, 637, 715 bassline: .byte 14, 14, 18, 12, 14, 14, 20, 12, 14, 14, 18, 8, 10, 10, 4, 8 .byte 10, 10, 12, 12, 14, 14, 6, 6, 10, 10, 12, 12 bassbeat: .byte 0, 0, 1, 0, 0, 1, 0, 1 arpseq1: .byte 0x00, 0x12, 0x00, 0x62 .byte 0x00, 0x12, 0x00, 0x17 .byte 0x00, 0x12, 0x00, 0x12 .byte 0x33, 0x22, 0x00, 0x45 arpseq2: .byte 0, 1, 0, 1, 0, 1, 0, 2, 3, 3 arptiming: .byte 0x0C, 0x30, 0xFB, 0x0C arpeggio: .byte 0x24, 0x6A .byte 0x46, 0x9C .byte 0x13, 0x59 .byte 0x02, 0x47 .byte 0x24, 0x59 .byte 0x24, 0x58 .byte 0x57, 0xAD .byte 0x35, 0x9B leadtimes: .byte 1, 2, 3, 4, 5, 6, 28, 14 leaddata: .byte 0x67, 0x24, 0x20, 0x27, 0x20, 0x28, 0x89, 0x0, 0x28, 0x20, 0x27, 0x20, 0x28, 0x89, 0x0, 0x28 .byte 0x20, 0x27, 0x20, 0x28, 0x86, 0x0, 0x44, 0x0, 0x63, 0x24, 0x62, 0xA1, 0xE0, 0xE0, 0xE0, 0xE0 .byte 0x20, 0x29, 0x20, 0x2A, 0x8B, 0x0, 0x4E, 0x0, 0x6F, 0x30, 0x71, 0xAF, 0xE0, 0xE0, 0xE0, 0xE0 .byte 0x20, 0x29, 0x20, 0x2A, 0x8B, 0x0, 0x4E, 0x0, 0x6F, 0x30, 0x6F, 0xAC, 0xE0, 0xE0, 0xE0, 0xE0 .byte 0x65, 0x22, 0x20, 0x65, 0x26, 0x87, 0x0, 0x68, 0x69, 0x2B, 0xAA, 0xC0, 0x67, 0x24, 0x20, 0x67 .byte 0x28, 0x89, 0x0, 0x68, 0x69, 0x2B, 0xAA, 0xC0, 0x65, 0x22, 0x20, 0x65, 0x26, 0xA7, 0x28, 0x20 .byte 0x69, 0x2B, 0xAA, 0x29, 0x20, 0x68, 0x29, 0xAA, 0x2B, 0x20, 0x69, 0x28, 0x69, 0x67, 0xE0 leadseq: .byte 0, 1, 0, 2, 0, 1, 0, 3, 4, 5, 6