10
20 MODE5:VDU28;31,?&30A,16
30 FORQ%=0TO2STEP2:P%=&900:[OPTQ%
40 CLD:LDY#0:STY&DC:STY&DE:LDA#&58:STA&DD:LDA#&62:STA&DF:LDX#&A
50 .a%LDA(&DC),Y:EOR(&DE),Y:STA(&DE),Y:INY:BNE a%:INC&DD:INC&DF:DEX:BNE a%
90 RTS:]:NEXT
100 sze0%=0:INPUT"1st Filename "fle0$:a%=OPENINfle0$:IFa%THENsze0%=EXT#a%:CLOSE#a%ELSEPRINT"File not found":STOP
110 sze1%=0:INPUT"2nd Filename "fle1$:a%=OPENINfle1$:IFa%THENsze1%=EXT#a%:CLOSE#a%ELSEPRINT"File not found":STOP
120 IFsze0%=0ORsze1%=0THENEND
130 z%=0:A%=3:X%=79:Y%=0
140 REPEAT?79=OPENINfle0$:!80=&5800
150 !84=&A00:!88=z%:CALL&FFD1:CLOSE#?79
160 ?79=OPENINfle1$:!80=&6200
170 !84=&A00:!88=z%:CALL&FFD1:CLOSE#?79
180 PRINT;~z%" ";:CALL&900
190 a%=GET:PRINT:z%=z%+&A00
200 UNTILz%>=sze0%ANDz%>=sze1%