10 ;      FINESCROLL RUTINE
20 ;  written in assembler editor
30 ;        by NIR DAREY
40 ;
0100          *=$6006
0110 ;  initialise the display list
0120          LDA #$80
0130          STA 560
0140          LDA #$60
0150          STA 561
0160 ;  initialise the VBI
0170          LDA #$07
0180          LDY #$30
0190          LDX #$60
0200          JSR $E45C
0205          RTS
0300 ;     Scroll Rutine
0305 ;
0310         *=$6030
0320         DEC $6000
0330         LDA $6000
0340          STA $D404;enable scroll
0350          BPL EXIT ; if N=0
0360          LDA #$FA
0370          STA $6000
0380          STA $D404
0385          JMP DELAY
0390 BACK     DEC $6083;START intr.
0400 EXIT     JMP $E462;exit VBI
0410 ; DL DATA
0420 ;
0425          *=$6080
0430  .BYTE 112,112
0440  .BYTE $52,$00,$63 ;calling VBI
0450  .BYTE 66,64,188
0460  .BYTE 2,2,2,2,2,2,2,2,2,2,2,2,2
0470  .BYTE 2,2,2,2,2,2,2,2,2,2
0480  .BYTE $41,$80,$60
0500 ; SCROLL TEXT
0510 ;
0520          *=$6300
0530  .BYTE ".........................................."
0540  .BYTE "this.is.one.page.scroll.rutine.in.vbi.very.easy.to.follow.it.was.written.in.assembler."
0550  .BYTE "by.nir.darey..i.hope.you.could.follow.the.listing.if.you.have.any.problem.just.let.me.know."
0560  .BYTE "and.i.will.try.to.help..greetings.to.all.atari.users..."
0600 DELAY   LDA #$00
0610         STA 20
0620 WAIT    LDA 20
0630         CMP 50
0640         BNE RETRN
0650         JMP WAIT
0660 RETRN   JMP BACK