1000 REM THIS ROUTINE CREATES AND ACCESSES RANDOM ACCESS FILES FOR FIXED›1001 REM LENGTH RECORDS›1002 REM ›1003 REM ... COMMANDS ARE›1004 REM CMD=1 WRITE   NTH RECORD›1005 REM CMD=2 READ    NTH RECORD›1006 REM CMD=3 UPDATE NTH RECORD›1007 REM ›1008 REM RECORD$ IS THE INPUT/OUTPUT RECORD›1009 REM N IS THE RECORD NUMBER›1010 REM INDEX IS A TWO DIMENSIONAL ARRAY DIM'ED INDEX(1,RECNUM)›1015 REM INDEX HOLDS THE NOTE VALUES FOR ALL RECORDS›1020 REM THIS ROUTINE ASSUMES LOGICAL FILE #1 HAS BEEN OPENED FOR I/O›1100 REM ›1120 REM ROUTINE BEGINS AT 1200›1130 REM ›1200 ON CMD GOTO 2000,3000,4000›2000 REM ............................›2100 REM WRITE NTH RECORD›2200 NOTE #1,X,Y›2300 INDEX(SEC,N)=X:INDEX(BYTE,N)=Y›2400 ? #1;RECORD$:RETURN ›3000 REM ............................›3010 REM READ NTH RECORD›3020 REM ›3030 X=INDEX(SEC,N):Y=INDEX(BYTE,N)›3040 POINT #1,X,Y›3050 INPUT #1;RECORD$›3060 RETURN ›4000 REM ............................›4010 REM UPDATE NTH RECORD›4020 REM ›4040 X=INDEX(SEC,N):Y=INDEX(BYTE,N)›4050 POINT #1,X,Y›4060 ? #1;RECORD$›4070 RETURN ›