; da65 V2.18 - Git ece63f0
; Created:    2023-10-03 10:18:14
; Input file: bitsy.bye
; Page:       1

OPEN_BUFFER     := $0280
L2000           := $2000
L1400           := $1400

PRODOS_MLI      := $BF00
DEVNUM          := $BF30
BITMAP          := $BF58

DRVSM2          := $C082

INIT            := $FB2F
BASCALC         := $FBC1
BELL1           := $FBDD
VTAB            := $FC22
HOME            := $FC58
RDKEY           := $FD0C
SETKBD          := $FE89
SETVID          := $FE93

CLR80VID        := $C00C
CLR80COL        := $C000
NEWVIDEO        := $C029

.macpack apple2
.setcpu "6502"
.org    $1000

        cld
        lda     DRVSM2          ; turn all drive phases off
        cli
        sta     CLR80VID
        sta     CLR80COL
        jsr     SETVID
        jsr     SETKBD
        sta     $04FB
        jsr     INIT
        jsr     HOME
        ldx     #$DF
        lda     #$CF
L101E:  sta     BITMAP-$df,x    ; $BF58, aka BITMAP
        lda     L135F -$df,x    ; $134F
        sta     $7A,x           ; $0159
        lda     #$00
        txs
        inx
        bne     L101E
.setcpu "65816"                 ; this is a NOP on 65x02
        rep     #$02            ; reset processor status bits
.setcpu "6502"
        beq     L1034           ; branch-always on 6502
        inx                     ; only //gs
        stx     NEWVIDEO        ; only //gs
L1034:  inc     BITMAP+$17      ; bitmap of low 48k of memory
        ldx     #(L1356-L12FE-1)  ; $57
L1039:  lda     L12FE+1,x         ; $1356
        bmi     L1045
        jsr     BASCALC         ; row in a -> screen address in ($28)
        ldy     L1300,x
        .byte   $2C             ; mask next ...
L1045:  sta     ($28),y         ; store directly to $(SCREEN) from BASCALC
        dey
        dex
        bne     L1039
L104B:  sta     $0480,y
        sta     ($28),y
        dey
        bpl     L104B

; done drawing screen

        lda     DEVNUM          ; get current active slot (DSSS/0000)
        lsr     a               ; for 7, that's 0111/0000
        lsr     a               
        lsr     a               ; now 0000/1110
        tax
        inx
        cmp     #$10            ; legit slot?
        bcc     L1060
L105F:  dex
L1060:  jsr     OPEN_PREFIX
        beq     L105F
L1065:  lda     #>L1400
        sta     $7A+1
        sta     $58+1
        ldy     #<L1400
        sty     $7A
        sty     $58
        jsr     OPEN_FILE
        cpy     #$4C
        beq     L107B
        jsr     BELL1
L107B:  lda     #$00
        tay
        sta     ($7A),y
        tax
L1081:  stx     $5E
L1083:  ldx     #$22
        ldy     $57
        cpy     #$22
        bcs     L108D
        ldy     #$22
L108D:  dey
        lda     #$A0
        cpy     $57
        bcs     L1098
        lda     ($70),y
        ora     #$80
L1098:  sta     $0405,x
        sta     $0381,y
        dex
L109F:  bne     L108D
        ldx     #$02
        stx     $25
L10A5:  lda     $57,x
        sta     $59,x
        dex
        bne     L10A5
L10AC:  jsr     VTAB
        inc     $25
        ldy     #$14
        lda     #$A1
        sta     ($28),y
        lda     $61,x
L10B9:  sta     $0380,x
        lda     #$FF
        cpx     $5E
        bne     L10CC
        lda     $5A
        sta     $5C
        lda     $5B
        sta     $5D
        lda     #$3F
L10CC:  sta     $5F
        ldy     #$00
        lda     ($5A),y
        bmi     L10EF
        bne     L10DD
        ldy     #$10
        sta     ($5A),y
        tay
        beq     L10E4
L10DD:  lsr     a
        lsr     a
        lsr     a
        lsr     a
        and     #$07
        tay
L10E4:  lda     L1375,y
        ldy     #$00
        sta     ($28),y
        inc     $28
        bne     L10FD
L10EF:  lda     #$A0
        sta     ($28),y
        inc     $28
        inc     $28
        lda     #$AF
        and     $5F
        sta     ($28),y
L10FD:  lda     ($5A),y
        and     #$0F
        sta     $60
L1103:  lda     #$A0
        cpy     $60
        iny
        bcs     L1110
        lda     ($5A),y
        ora     #$80
        and     $5F
L1110:  sta     ($28),y
        cpy     #$11
        bne     L1103
        lda     #$0F
        adc     $5A
        sta     $5A
        bcc     L1120
        inc     $5B
L1120:  inx
        cpx     #$14
        bcc     L10AC
        stx     $29
        jsr     RDKEY           ; get keypress
        cmp     #$8D            ; CR?
        bne     L11A8

; try to load and execute the selected file
        jsr     PRODOS_MLI      ; SET_PREFIX
        .byte   $c6
        .word   L12FD
        bcs     L1191
        tay
        lda     ($5C),y
        beq     L11A2
        sty     $7A
        ldx     #$20
L113F:  stx     $7B
        cmp     #$60
        and     #$0F
        bcs     L1174
        sta     ($5C),y
        inc     $74
        dey
        jsr     OPEN_FILE
        dey
        bmi     L1164
        ldx     L10B9+1
        lda     #$C3
        sta     $0305,x
        ldy     #$FF
L115C:  jsr     OPEN_FILE
        dec     $74
        dey
        bpl     L11A2
L1164:  ldy     #$0F
L1166:  lda     ($5C),y
        sta     $2006,y
        dey
        bpl     L1166
EXEC_FILE:  jsr     HOME
        jmp     L2000

L1174:  tay
        adc     $57
        sta     $57
        tax
L117A:  lda     ($5C),y
        sta     OPEN_BUFFER,x
        dex
        dey
        bpl     L117A
        asl     a
        lda     #$AF
        sta     $0281,x
        bcs     L11A5
        jsr     OPEN_FILE
        tya
        beq     EXEC_FILE
L1191:  jsr     BELL1

BROWSER_BACK:  ldy     $57
L1196:  lda     ($73),y
        dey
        beq     L11A2
        tax
        bpl     L1196
        sty     $57
        bmi     L11A5
L11A2:  jsr     BELL1
L11A5:  jmp     L1065

L11A8:  ldx     $5E
        cmp     #$95            ; right-arrow?
        bne     L11E5
L11AE:  inx
        ldy     #$10
        lda     ($5C),y
        beq     L11D1
        cpx     #$0A
        bcc     L120E
        inc     $59
        ldy     #$40
        lda     ($58),y
        dec     $59
        tay
        beq     L120E
        lda     $58
        ldy     $59
        adc     #$0F
        bcc     L11CD
        iny
L11CD:  sta     $58
        sty     $59
L11D1:  jmp     L1083

L11D4:  eor     #$F8
        rol     a
        tax
        eor     $56
        lsr     a
        bne     L11E0
        bcs     L11E0
        dex
L11E0:  jsr     OPEN_PREFIX
        bpl     L11A5
L11E5:  cmp     #$9B            ; ESC?
        beq     BROWSER_BACK
        cmp     #$C1            ; A?
        bcs     L1221           ; branch if less than or equal to ...
        adc     #$48            ; carry clear, so assume this is minimum $FA
        cmp     #$F9
        bcs     L11D4           ; if we are <= $F9, go to L11D4
        sbc     #$CF            ; now minimum $2c - "+"
        beq     L1201
        tay
        dey
        beq     L121C
        dey
        beq     L11AE
        dey
        bne     L11D1
L1201:  ldy     $59
        lda     $58
        bne     L1211
        cpy     #$14
        bne     L1211
L120B:  dex
L120C:  bmi     L11D1
L120E:  jmp     L1081

L1211:  cpx     #$0A
        bcs     L120B
        sbc     #$0F
        bcs     L11CD
        dey
        bcc     L11CD
L121C:  ldx     $56
        jmp     L105F

L1221:  and     #$5F
        sta     $60
        ldx     #$00
        ldy     $5C
        stx     $5C
        inx
L122C:  tya
        clc
        adc     #$10
        tay
        bcc     L1235
        inc     $5D
L1235:  lda     ($5C),y
        beq     L124A
        iny
        lda     ($5C),y
        dey
        cmp     $60
        bne     L122C
        sty     $58
        lda     $5D
        sta     $59
        jmp     L107B

L124A:  dex
        bmi     L120C
        tay
        lda     #$14
        sta     $5D
        bne     L1235

OPEN_PREFIX:  txa
        and     #$0F
        sta     $56
        lsr     a
        beq     L127C
        php
        ora     #$b0
        sta     $0401
        asl     a
        asl     a
        asl     a
        asl     a
        plp
        ldy     #$B1
        bcs     L126E
        ora     #$80
        iny
L126E:  sta     $6F
L1270:  sty     $0404
        jsr     PRODOS_MLI      ; online
        .byte   $c5
        .word   $006e
        lda     $0281
L127C:  ldy     #$AF
        sty     $0281
        and     #$0F
        tay
        clc
        adc     #$0E
        sta     $0380
        adc     #$74
        sta     L10B9+1
        iny
        sty     $57
        dey
        rts

OPEN_FILE:  lda     $57
        sta     OPEN_BUFFER
        jsr     PRODOS_MLI      ; open
        .byte   $c8
        .word   $0072
        bcs     BB_EXIT
        lda     $77
        sta     $79
        sty     $7D
        lda     #$2B
        ldx     #$0D
        .byte   $2C             ; mask next
L12AC:  lda     #$27
        dex
        bne     L12B5
        lda     #$2C
        ldx     #$0D
L12B5:  sta     $7C
        jsr     PRODOS_MLI      ; read bytes from open file
        .byte   $ca
        .word   $0078
        iny
        beq     BB_EXIT
        lsr     $7E
        beq     BB_EXIT
        tay
        lda     ($7A),y
        and     #$8F
        sta     ($7A),y
        asl     a
        beq     L12AC
        ldy     #$10
        lda     ($7A),y
        ldy     #$07
L12D4:  dey
        beq     L12DC
        cmp     L136E,y
        bne     L12D4
L12DC:  tya
        asl     a
        asl     a
        asl     a
        asl     a
        ldy     #$00
        ora     ($7A),y
        sta     ($7A),y
        lda     $7A
        adc     #$10
        sta     $7A
        bcc     L12AC
        inc     $7B
        bne     L12AC
BB_EXIT:  tay
        jsr     PRODOS_MLI      ; close all open files
        .byte   $cc
        .word   CLOSE_ALL
        rts

; ProDOS MLI call parameters here

CLOSE_ALL:  .byte   1, 0    ; one parameter, no reference, so close all
L12FD:  .byte   1
L12FE:  .word   OPEN_BUFFER

L1300:  .byte   $ad, $16, $29
        scrcode "BITSY  BYE"
        .byte   $05, $24
        scrcode "BY"
        .byte   $0a, $20
        scrcode "J.BROOKS"
        .byte   $0f, $23
        scrcode "P.FERRIE"
        .byte   $12, $23
        scrcode "RETURN:SELECT"
        .byte   $17, $0d
        scrcode "ESC:BACK"
        .byte   $17
L134F:  .byte   $18        ; $18 is L134F
        scrcode "TAB,#:NEW VOL"
        .byte   $17, $28
L135F:  scrcode "S6,D1:"
        .byte   $00
L1356:  .byte   $06
L135q:  scrcode "/BASIS.SYSTEM"

        .byte   $02, $00, $81, $02, $03, $80, $02, $00, $0b, $00
L136E:  .byte   $04, $FA, $06, $fc, $04
        .byte   $B3
        .byte   $FF
L1375:  .byte   $a0, $c9, $c2, $c1, $d4, $ad, $ad