Prevent scrolling on C64

// noscroll.asm by Scan
// see http://unusedino.de/ec64/technical/misc/c64/romlisting.html for the kernal routines patched

.pc = $0801 "Basic UpStart"
basic:
:BasicUpstart2(start)

.pc = * "Entrypoint"
start:          sei
next:           ldx #$00
!:              lda src1:$a000,x
                sta dst1:$a000,x
                lda src2:$e000,x
                sta dst2:$e000,x
                dex
                bne !-
                inc src2+1
                beq done
                inc src1+1
                inc dst1+1
                inc dst2+1
                bne next
done:           ldx #patchend-patch
!:              lda patch,x
                sta $e8ea,x
                dex
                bpl !-
                lda #RTS
                sta $e9c8
                sta $e9ff
                lda #%00110101
                sta $01
                cli
                rts

patch:          clc
                ldx #$00
                ldy $d3
                jsr $e50a
                rts
patchend: