; VMW Chiptune Player .include "zp.inc" LZ4_BUFFER EQU $4000 CHUNK_BUFFER EQU $6000 CHUNKSIZE EQU $3 ;============================= ; Setup ;============================= jsr HOME jsr TEXT ; init variables lda #0 sta DRAW_PAGE sta CH sta CV sta DONE_PLAYING sta XPOS sta MB_FRAME_DIFF ; print detection message lda #mocking_message sta OUTH jsr move_and_print ; print it jsr mockingboard_detect_slot4 ; call detection routine cpx #$1 beq mockingboard_found lda #not_message sta OUTH inc CV jsr move_and_print jmp forever_loop ; and wait forever mockingboard_found: ; lda #found_message ; sta OUTH ; inc CV ; jsr move_and_print ;============================ ; Init the Mockingboard ;============================ jsr mockingboard_init jsr reset_ay_both jsr clear_ay_both ;========================= ; Setup Interrupt Handler ;========================= ; Vector address goes to 0x3fe/0x3ff ; FIXME: should chain any existing handler lda #interrupt_handler sta $03ff ;============================ ; Enable 50Hz clock on 6522 ;============================ lda #$40 ; Continuous interrupts, don't touch PB7 sta $C40B ; ACR register lda #$7F ; clear all interrupt flags sta $C40E ; IER register (interrupt enable) lda #$C0 sta $C40D ; IFR: 1100, enable interrupt on timer one oflow sta $C40E ; IER: 1100, enable timer one interrupt lda #$E7 sta $C404 ; write into low-order latch lda #$4f sta $C405 ; write into high-order latch, ; load both values into counter ; clear interrupt and start counting ; 4fe7 / 1e6 = .020s, 50Hz ;============================ ; Draw title screen ;============================ jsr set_gr_page0 lda #$4 sta DRAW_PAGE jsr clear_screens lda #chip_title sta GBASH ; Load image lda #<$400 sta BASL lda #>$400 sta BASH jsr load_rle_gr ;=========================== ; load first song ;=========================== jsr new_song ;============================ ; Enable 6502 interrupts ;============================ cli ; clear interrupt mask ;============================ ; Init Background ;============================ ; jsr clear_screens ; clear top/bottom of page 0/1 jsr set_gr_page0 lda #0 sta DRAW_PAGE sta SCREEN_Y ;============================ ; Loop forever ;============================ playing_loop: ;============================ ; rasters ;============================ jsr clear_top jsr draw_rasters jsr volume_bars jsr page_flip lda DONE_PLAYING beq playing_loop done_play: ; FIXME: disable timer on 6522 ; FIXME: unhook interrupt handler sei ; disable interrupts jsr clear_ay_both lda #0 sta CH lda #21 sta CV lda #done_message sta OUTH jsr move_and_print forever_loop: jmp forever_loop ;============================= ;============================= ; simple interrupt handler ;============================= ;============================= ; On Apple II/6502 the interrupt handler jumps to address in 0xfffe ; This is in the ROM, which saves the registers ; on older IIe it saved A to $45 (which could mess with DISK II) ; newer IIe doesn't do that. ; It then calculates if it is a BRK or not (which trashes A) ; Then it sets up the stack like an interrupt and calls 0x3fe interrupt_handler: pha ; save A ; Should we save X and Y too? inc $0404 ; debug bit $C404 ; can clear 6522 interrupt by reading T1C-L inc FRAME_COUNT lda FRAME_COUNT cmp #50 bne frame_good lda #$0 sta FRAME_COUNT update_second_ones: inc $7d0+18 inc $bd0+18 lda $bd0+18 cmp #$ba ; one past '9' bne frame_good lda #'0'+$80 sta $7d0+18 sta $bd0+18 update_second_tens: inc $7d0+17 inc $bd0+17 lda $bd0+17 cmp #$b6 ; 6 bne frame_good lda #'0'+$80 sta $7d0+17 sta $bd0+17 update_minutes: inc $7d0+15 inc $bd0+15 ; we don't handle > 9:59 songs yet frame_good: ldy MB_FRAME_DIFF ldx #0 mb_write_loop: lda (INL),y cpx #13 bne mb_not_13 cmp #$ff beq skip_r13 mb_not_13: sta MB_VALUE cpx #8 bne mb_not_8 and #$f sta A_VOLUME mb_not_8: cpx #9 bne mb_not_9 and #$f sta B_VOLUME mb_not_9: cpx #10 bne mb_not_10 and #$f sta C_VOLUME mb_not_10: ; INLINE? jsr write_ay_both ; assume 3 channel (not six) ; so write same to both left/write clc lda INH adc #CHUNKSIZE sta INH inx cpx #14 bmi mb_write_loop skip_r13: lda MB_CHUNK clc adc #>CHUNK_BUFFER sta INH inc MB_FRAME_DIFF bne done_interrupt wraparound: inc MB_CHUNK lda MB_CHUNK cmp #CHUNKSIZE bne chunk_good lda #0 sta MB_CHUNK chunk_good: done_interrupt: pla rti ;================= ; load a new song ;================= new_song: lda #0 sta A_VOLUME lda #0 sta B_VOLUME lda #0 sta C_VOLUME ;=========================== ; init pointer to the music ;=========================== jsr read_file lda #>CHUNK_BUFFER sta INH lda #file_info sta OUTH ldy #0 ; FIXME: optimize lda #20 sta CV lda (OUTL),Y sta CH inc OUTL bne bloop1 inc OUTH bloop1: jsr print_both_pages iny tya ldy #0 clc adc OUTL sta OUTL lda OUTH adc #$0 sta OUTH lda #21 sta CV lda (OUTL),Y sta CH inc OUTL bne bloop2 inc OUTH bloop2: jsr print_both_pages iny tya ldy #0 clc adc OUTL sta OUTL lda OUTH adc #$0 sta OUTH lda #23 sta CV lda (OUTL),Y sta CH inc OUTL bne bloop3 inc OUTH bloop3: jsr print_both_pages rts ;========= ;routines ;========= .include "../asm_routines/gr_offsets.s" .include "../asm_routines/text_print.s" .include "../asm_routines/mockingboard_a.s" .include "../asm_routines/gr_fast_clear.s" .include "../asm_routines/pageflip.s" .include "../asm_routines/gr_unrle.s" .include "../asm_routines/gr_setpage.s" .include "../asm_routines/dos33_routines.s" .include "../asm_routines/gr_hlin.s" .include "../asm_routines/lz4_decode.s" .include "rasterbars.s" .include "volume_bars.s" ;=========== ; File info ;=========== file_info: .byte 1 .asciiz "INTRO2: JUNGAR OF BIT WORLD FROM KIEV" .byte 5 .asciiz "BY: SURGEON (ALEKSEY LUTSENKO)" .byte 15 .asciiz "0:00 / 0:00" ;========= ; strings ;========= mocking_message: .asciiz "LOOKING FOR MOCKINGBOARD IN SLOT #4" not_message: .byte "NOT " found_message: .asciiz "FOUND" done_message: .asciiz "DONE PLAYING" ;============ ; graphics ;============ .include "chip_title.inc"