From 13fbb827eea143680c0945367617db539a5f8115 Mon Sep 17 00:00:00 2001 From: Vince Weaver Date: Thu, 14 Mar 2024 00:24:31 -0400 Subject: [PATCH] lovebyte: dtv: missing file --- demos/lovebyte2024/dtv_1k/duet.s | 202 +++++++++++++++++++++++++++++++ 1 file changed, 202 insertions(+) create mode 100644 demos/lovebyte2024/dtv_1k/duet.s diff --git a/demos/lovebyte2024/dtv_1k/duet.s b/demos/lovebyte2024/dtv_1k/duet.s new file mode 100644 index 00000000..e568a3bd --- /dev/null +++ b/demos/lovebyte2024/dtv_1k/duet.s @@ -0,0 +1,202 @@ + +; *************************************************************************** +; * Copyright (C) 1979-2015 by Paul Lutus * +; * http://arachnoid.com/administration * +; * * +; * This program is free software; you can redistribute it and/or modify * +; * it under the terms of the GNU General Public License as published by * +; * the Free Software Foundation; either version 2 of the License, or * +; * (at your option) any later version. * +; * * +; * This program is distributed in the hope that it will be useful, * +; * but WITHOUT ANY WARRANTY; without even the implied warranty of * +; * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the * +; * GNU General Public License for more details. * +; * * +; * You should have received a copy of the GNU General Public License * +; * along with this program; if not, write to the * +; * Free Software Foundation, Inc., * +; * 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA. * +; *************************************************************************** + +; Electric Duet Player Routine circa 1980 + +; Most comments added by Vince Weaver + +;.define EQU = + +; These are all "Free" zero page locations +;FREQ1 EQU $06 +;FREQ2 EQU $07 +;DURATION EQU $08 +;INSTRUMENT1 EQU $09 +;INSTRUMENT2 EQU $1D +;MADDRL EQU $1E +;MADDRH EQU $1F +;LOC4E EQU $4E +;COUNT256 EQU $4F + +play_ed: + LDA #$01 ; 900: A9 01 ; 2 *!* + STA INSTRUMENT1 ; 902: 85 09 ; 3 set default + STA INSTRUMENT2 ; 904: 85 1D ; 3 instruments + PHA ; 906: 48 ; 3 1 on stack + PHA ; 907: 48 ; 3 1 on stack + PHA ; 908: 48 ; 3 1 on stack + BNE load_triplet ; 909: D0 15 ; 4 *!* start decoding + +change_instrmnt: + INY ; 90B: C8 ; 2 + LDA (MADDRL),Y ; 90C: B1 1E ; 5 *!* load next byte + STA INSTRUMENT1 ; 90E: 85 09 ; 3 save instrument + INY ; 910: C8 ; 2 + LDA (MADDRL),Y ; 911: B1 1E ; 5 *!* load next byte + STA INSTRUMENT2 ; 913: 85 1D ; 3 save instrument + +triplet_loop: + ldy #0 + +;==================================== + jsr display_lyrics_ed +; inc FRAME_COUNT +;==================================== + + LDA MADDRL ; 915: A5 1E ; 3 *!* increment pointer + CLC ; 917: 18 ; 2 by three + ADC #$03 ; 918: 69 03 ; 2 *!* + STA MADDRL ; 91A: 85 1E ; 3 + + BCC load_triplet ; 91C: 90 02 ; 4 *!* if overflow + INC MADDRH ; 91E: E6 1F ; 5 update high byte + +load_triplet: + LDY #$00 ; 920: A0 00 ; 2 *!* Set Y to zero + LDA (MADDRL),Y ; 922: B1 1E ; 5 *!* Load first byte + CMP #$01 ; 924: C9 01 ; 2 Compare to 1 + BEQ change_instrmnt ; 926: F0 E3 ; 4 *!* If one change inst + BCS play_note ; 928: B0 0D ; 4 *!* If >1, then duration + PLA ; 92A: 68 ; 4 pop off stack + PLA ; 92B: 68 ; 4 pop off stack + PLA ; 92C: 68 ; 4 pop off stack + + ; fallthrough if first byte was zero + + ; Load byte from music stream + ; Set X=EOR if note zero, set X=CMP if it is + +load_freq: + LDX #$49 ; 92D: A2 49 ; 2 *!* X=0x49 (EOR opcode) + INY ; 92F: C8 ; 2 increment to next byte + LDA (MADDRL),Y ; 930: B1 1E ; 5 *!* load next byte + BNE exit_player ; 932: D0 02 ; 4 *!* if not zero + LDX #$C9 ; 934: A2 C9 ; 2 *!* X=0xC9 (CMP opcode) + +exit_player: + ; if byte0==0 and byte1==0 then done playing + RTS ; 936: 60 ; 6 return + + + ; We've got a duration/note/note triplet here + +play_note: + STA DURATION ; 937: 85 08 ; 3 store out duration + JSR load_freq ; 939: 20 2D09 ; 6 get freq#1 + STX selfmodify1 ; 93C: 8E 8309 ; 4 if 0 self-modify EOR/CMP + STA FREQ1 ; 93F: 85 06 ; 3 + LDX INSTRUMENT1 ; 941: A6 09 ; 3 *!* + +instr1_adjust: + LSR A ; 943: 4A ; 2 rshift freq by inst# + DEX ; 944: CA ; 2 + BNE instr1_adjust ; 945: D0 FC ; 4 *!* + STA selfmodify2+1 ; 947: 8D 7C09 ; 4 self-modify a CPY + + JSR load_freq ; 94A: 20 2D09 ; 6 get freq#2 + STX selfmodify3 ; 94D: 8E BB09 ; 4 if 0 self-modify EOR/CMP + STA FREQ2 ; 950: 85 07 ; 3 + LDX INSTRUMENT2 ; 952: A6 1D ; 3 *!* +instr2_adjust: + LSR A ; 954: 4A ; 2 rshift freq by inst# + DEX ; 955: CA ; 2 + BNE instr2_adjust ; 956: D0 FC ; 4 *!* + STA selfmodify4+1 ; 958: 8D B409 ; 4 self modify a CPX + + PLA ; 95B: 68 ; 4 + TAY ; 95C: A8 ; 2 + PLA ; 95D: 68 ; 4 + TAX ; 95E: AA ; 2 + PLA ; 95F: 68 ; 4 + BNE label8 ; 960: D0 03 ; 4 *!* + +label99: + BIT $C030 ; 962: 2C 30C0 ; 4 SPEAKER +label8: + CMP #$00 ; 965: C9 00 ; 2 + BMI label7 ; 967: 30 03 ; 4 *!* + NOP ; 969: EA ; 2 + BPL label9 ; 96A: 10 03 ; 4 *!* +label7: + BIT $C030 ; 96C: 2C 30C0 ; 4 SPEAKER +label9: + STA LOC4E ; 96F: 85 4E ; 3 + BIT $C000 ; 971: 2C 00C0 ; 4 KEYBOARD DATA + BMI exit_player ; 974: 30 C0 ; 4 *!* if keypress, exit + DEY ; 976: 88 ; 2 + BNE selfmodify2 ; 977: D0 02 ; 4 *!* + BEQ label11 ; 979: F0 06 ; 4 *!* +selfmodify2: + CPY #$00 ; 97B: C0 00 ; 2 + BEQ selfmodify1 ; 97D: F0 04 ; 4 *!* !!! + BNE label13 ; 97F: D0 04 ; 4 *!* +label11: + LDY FREQ1 ; 981: A4 06 ; 3 *!* +selfmodify1: + EOR #$40 ; 983: 49 40 ; 2 *!* !!! +label13: + BIT LOC4E ; 985: 24 4E ; 3 + BVC label14 ; 987: 50 07 ; 4 *!* + BVS label15 ; 989: 70 00 ; 4 *!* +label15: + BPL label16 ; 98B: 10 09 ; 4 *!* + NOP ; 98D: EA ; 2 + BMI label17 ; 98E: 30 09 ; 4 *!* +label14: + NOP ; 990: EA ; 2 + BMI label16 ; 991: 30 03 ; 4 *!* + NOP ; 993: EA ; 2 + BPL label17 ; 994: 10 03 ; 4 *!* +label16: + CMP $C030 ; 996: CD 30C0 ; 4 SPEAKER +label17: + DEC COUNT256 ; 999: C6 4F ; 5 div by 256 counter + BNE label18 ; 99B: D0 11 ; 4 *!* + + DEC DURATION ; 99D: C6 08 ; 5 + BNE label18 ; 99F: D0 0D ; 4 *!* + BVC label19 ; 9A1: 50 03 ; 4 *!* + BIT $C030 ; 9A3: 2C 30C0 ; 4 SPEAKER +label19: + PHA ; 9A6: 48 ; 3 + TXA ; 9A7: 8A ; 2 + PHA ; 9A8: 48 ; 3 + TYA ; 9A9: 98 ; 2 + PHA ; 9AA: 48 ; 3 + JMP triplet_loop ; 9AB: 4C 1509 ; 3 + +label18: + DEX ; 9AE: CA ; 2 + BNE selfmodify4 ; 9AF: D0 02 ; 4 *!* + BEQ label21 ; 9B1: F0 06 ; 4 *!* +selfmodify4: + CPX #$00 ; 9B3: E0 00 ; 2 + BEQ selfmodify3 ; 9B5: F0 04 ; 4 *!* !!! + BNE label23 ; 9B7: D0 04 ; 4 *!* +label21: + LDX FREQ2 ; 9B9: A6 07 ; 3 *!* +selfmodify3: + EOR #$80 ; 9BB: 49 80 ; 2 *!* !!! +label23: + BVS label99 ; 9BD: 70 A3 ; 4 *!* + NOP ; 9BF: EA ; 2 + BVC label8 ; 9C0: 50 A3 ; 4 *!* +