mini note file viewer. rev2 with multi-page support. (c64)

micro note

;
;  a minimal noter example with generated audio, BASIC header and multi-page support
;

        * = $801

        ; 0 SYS4096
        byte    $0B, $08, $00, $00, $9E, '4', '0', '9', '6', $00, $00, $00

        * = $1000

init    
        lda #6
        sta $d020       ; border color = screen color
        
start   
        lda txt         ; get char

        inc start+1     ; self-modifying code to alter the txt offset
        bne cont
        inc start+2

cont
        cmp #$ff        ; end of page?
        beq wait_s      ; -> wait

        cmp #$fe        ; end of text?
        bne putchar     ; no? -> get next char

        lda <txt        ; otherwise: wrap around
        sta start+1     ; re-init offset
        lda >txt
        sta start+2

        jmp start
        
putchar
        jsr $ffd2       ; KERNAL chrout
        jmp start

wait_s
        lda #0          ; clear key buffer
        sta $c6

wait    
        inx
        lda $a2        
        sta $d418,x    ; funky glitch audio :)
        lda $c6
        beq wait
        jmp start

txt     
        byte 147, 14, 154    ; clear screen, upper/lower-case, light-blue
        text "mICRO nOTE wITH aUDIO"
        byte 13, 13, 13
        text "lorem ipsum"
        byte 13, 13
        text "0123456789"
        byte 13, 13, 150 ; 150 = light-red
        text "tHE lAZY bROWN fOX!"
        byte $ff ; end of page
        byte 147
        text "pAGE tWO!"
        byte 13, 13, 13, 158 ; 158 = yellow
        text "(end)"
        byte $ff, $fe ; end of page and end of text