Commodore 1541 - Page 47

When working with a new relative file that will soon be very large, it will save
much lime to create a record at the projected end of the Tile. In other words, if you ex
pert the file to be 1000 records long, create a record* 1000 as soon as the file is created.
This will force the DOS lo create all intermediate records, making later use of those
records much faster.
EXAMPLE OF CREATING LARGE FILE:
OPEN 1.8, 15: OPEN 2, 8, 2, ■■fl:REL,L," +CHRS(60)
PRINTS. "P" CHRS(2 + 96) CHR$(0) CHRS(4) CHR$(l)
PRINTS, "END"
CLOSE 2: CLOSE 1
PROGRAM AND EXPLANATION
1 REM RELATIVE FILE PROGRAM
2 DIM AS (5):DIM CS{5) :PRiNT" □ "
3 PRINT "HIT Fl TO CONSTRUCT A RELATIVE FILE"
4 PRINT "HIT F3 TO READ A RELATIVE FILE"
5 PRINT "HIT F5 TO READ THE ERROR CHANNEL":GOSUB 5000
6
INPUT"ENTER RELATIVE FILE NAME";Z3
8 OPEN2.8,2,Z$+",L," + CHR$<50) :REM CREATE THE RELATIVE FILE
9 OPENl.8,15
11 GOSUB 1000
20 FOR 1 = 1 TO 5
30 PRINTS,■■P"CHRS(2 + 96)CHR$(l)CHRS{0)CHRS(i):REM POSITION THE
RECORD POINTER
40 PRINT "ENTER A NAME"
50 INPUT A$(I)
60 PRINT#2,A$,(I)
63 INPUT "ENTER ADDITIONAL INFO";CS(I)
65 PRINT#l,"P"CHRS(2 + 96)CHRS(I)CHRS(0)CHRS(25) :REM POSITION
POINTER TO 25TH CHARACTER
67 PRINT #2,CS(I)
70 NEXT I
75 PRINT"DO YOU WISH TO REPLACE A RECORD":INPUT DS
76 1FD$ = "N"THEN8O
77 GOSUB 8000
78 GO TO 75
80 PRINT"THE RELATIVE FILE IS CONSTRUCTED"
82 FOR DE = 1 TO 2500:NEXT DE:GOSUB 6000
85 CLOSE 2
90 END:STOP
100 INPUT "ENTER DESIRED FILE TO READ";Z$
105 OPEN 2,8,2,ZS:OPEN 1,8,15
106 PRINT "READING "ZS
110 FORI=1TO5
115 REMFORI = 5TO1 STEP-1
130 PRIN™,"P"CHRS(2 + 96)CHR$(I)CHR$(O)CHR$(1)
160 INPUT#2,AS(I)
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