10 OPEN"CAS:ΘΙ-ΘΙ" FOR OUTPUT AS #1
20 FOR K=1 TO 500:PRINT #1,K;:NEXT
30 CLOSE #1
40 STOP
50 CLEAR 1000
60 OPEN"CAS:ΘΙ-ΘΙ" FOR INPUT AS #1
70 LINE INPUT #1,M$:PRINT M$;
80 IF NOT EOF(1) THEN 70
90 END