99 Bottles.s

;$VER: 99bottles.s v1.00 by Zeb (26-Aug-2018)

    output  ram:99Bottles

ProgStart:
    move.l  4.w,a6
    lea DosName(pc),a1
    moveq.l #0,d0
    jsr -$228(a6)   ;OpenLibrary(a1,d0)exec
    move.l  d0,DosName
    beq.b   Fatal
    move.l  d0,a6
    jsr -$3c(a6)    ;Output()dos
    move.l  d0,d6
    beq.b   ClDos

    moveq.l #100,d7
Loop:   move.l  d7,d4
    lea Bottle(pc),a4

    move.l  d4,d5
    subq    #1,d5
    divu    #10,d5
    move.b  d5,(a4)
    add.b   #"0",(a4)+
    swap    d5
    move.b  d5,(a4)
    add.b   #"0",(a4)
    cmpi    #9,d4
    bls.b   SingleDigit
    subq    #1,a4
SingleDigit:

    move.l  d6,d1       ;Show the first bit
    lea Bottle(pc),a0
    move.l  a0,d2
    moveq.l #9,d3
    jsr -$30(a6)    ;Write(d1,d2,d3)dos

    cmpi    #2,d7       ;Check for singular (remember, our counter is +1 due to our way of exiting the loop
    beq.b   Singular
    lea Plural(pc),a0
    move.l  d6,d1
    move.l  a0,d2
    moveq.l #1,d3
    jsr -$30(a6)    ;Write(d1,d2,d3)dos
Singular:
    lea EndText(pc),a0
    move.l  d6,d1
    move.l  a0,d2
    moveq.l #21,d3
    jsr -$30(a6)    ;Write(d1,d2,d3)dos

    subq.l  #1,d7
    bne.b   Loop

ClDos:  move.l  a6,a1
    move.l  4.w,a6
    jsr -$19e(a6)   ;CloseLibrary(a1)exec
Fatal:  moveq.l #0,d0
    rts

DosName:
    dc.b    'dos.library',0
    even
Bottle:
    dc.b    'XX bottle'
    even
Plural: dc.b    's',0
EndText:
    dc.b    ' of beer on the wall',$a
    even
    end