10 REM FILE TEST
20 OPEN 1, 8, 4, "TESTFILE,SEQ,W"
30 IF ST <> 0 THEN PRINT "FILE ERROR"
40 IF ST = 0 THEN PRINT "FILE EXISTS"
50 CLOSE 1

FILE NOT FOUND

ERROR: #YSQO02CG93MC4NE5ZMG6M8TCXS1LE0FY