10 REM (C) 1988 UPTIME MAGAZINE
20 REM (C) 1988 SOFTDISK PUBLISHING INC.
30 REM AUTHOR: NOEL NYMAN
40 REM GRAY BORDER, BLACK SCREEN, LIGHT GREEN TEXT
45 SYS65409
50 POKE53280,11:POKE53281,0:POKE646,13
60 REM Q$=QUOTES, FORCE UPPER/LOWER CASE, RUN/STOP DISABLED
70 Q$=CHR$(34):PRINTCHR$(14)CHR$(8):SP$="                   ":POKE808,234
80 REM --- SYS (null),X,Y PLACES CURSOR AT ROW X, COLUMN Y ---
90 Q=679:FORX=QTO706:READA:POKEX,A:NEXT
100 DATA 32,253,174,32,158,173,32,170,177,132,2,32,253,174,32,158
110 DATA 173,32,170,177,166,2,76,240,255,56,176,250
120 REM SKIP SUB-ROUTINES
130 GOTO560
140 REM *** CLEAR SCREEN TO LINE 23 STARTING AT LINE 'X' ***
150 X=10:GOSUB160:SYSQ,10,3:RETURN
160 FORY=XTO23:SYSQ,Y,0:SYS 59903:POKEY+217,PEEK(Y+217)OR128:NEXT
170 RETURN
180 REM *** FILTER KEYBOARD INPUT FOR STRING ***
190 REM ---RETURNS STRING IN XX$ LENGTH 'LL' OR SMALLER---
200 XX$="":XB=65:XE=90:GOTO220:REM LOWER CASE ALPHA ONLY
210 XX$="":XB=48:XE=57:GOTO220:REM NUMERIC ONLY
220 GOSUB270:XA=ASC(CG$):IFXA=13ANDXX$<>""THENRETURN
230 IF(XA=20)AND(XX$<>"")THENPRINTCG$;:XX$=LEFT$(XX$,LEN(XX$)-1):GOTO220
240 IF(XA<XB)OR(XA>XE)GOTO220
250 IFLEN(XX$)>=LLGOTO220
260 PRINTCG$;:XX$=XX$+CG$:GOTO220
270 XL%=PEEK(211)
280 IF(XL%>39)THENXL%=XL%-40:GOTO280
290 XL%=XL%+PEEK(214)*40+1024:XC=54272+XL%
300 POKEXC,PEEK(646):XO%=PEEK(XL%):XT%=XO%:XQ%=128:IF(XO%>127)THENXQ%=-XQ%
310 XT%=XT%+XQ%:POKEXL%,XT%:XQ%=-XQ%
320 FORXR=1TO60
330 GETCG$:IF(CG$<>"")THENPOKEXL%,XO%:XR=61:NEXT:RETURN
340 NEXT:GOTO310
350 REM *** DELAY LOOP ***
360 REM --- ENTER WITH DELAY TIME IN X ---
370 FORA=1TOX:NEXT:RETURN
380 FORY=11TO16:SYSQ,6,Y:PRINT"[158]->[153]":X=50:GOSUB370:NEXT:RETURN
390 GOSUB420:SYSQ,5,19:PRINTSP$:SYSQ,6,19:PRINTSP$:RETURN
400 SYSQ,0,0:SYS59903:RETURN
410 FORY=16TO11STEP-1:SYSQ,6,Y:PRINT"<*":X=50:GOSUB370:NEXT:RETURN
420 SYSQ,6,11:PRINT"       ":RETURN
430 REM *** PROMPT ***
440 SYS679,24,1:PRINT"[152][211][208][193][195][197] [194][193][210] TO CONTINUE - [198]8 FOR [213][208][212][201][205][197][146][153]";
450 WAIT198,1:POKE198,0
460 IF(PEEK(631)=32)OR(PEEK(631)=13)THENWAIT197,64:RETURN
470 IFPEEK(631)<>140GOTO450
480 REM RE-ENTER UPTIME ENVIRONMENT
490 PRINTCHR$(9): REM ENABLE SHIFT/C=
500 POKE186,8: REM DEVICE #8
510 POKE808,237: REM RE-ENABLE RUN-STOP
520 LOAD"REBOOT",8
530 REM ***************************
540 REM   MAIN PROGRAM STARTS HERE
550 REM ***************************
560 PRINT"[147]"
570 PRINT"[158]       [182][183][183][183][183][183][183][183][183][183][183][183][183][183][183][183][183][183][183][183][183][183][183][183][183][181]
580 [153]"SYS       ABS PRINT(null)(null)RIGHT$(null)CHR$ (null)VAL(null)(null)VAL(null)(null)RIGHT$ATN(null) ASCRIGHT$(null)VAL(null) SYSINT
590 PRINT"       [182][175][175][175][175][175][175][175][175][175][175][175][175][175][175][175][175][175][175][175][175][175][175][175][175][181]
600 [153]"PRINT#     PUBLISHED BY (null)OFTDISK (null)UBLISHING
610 PRINT"     WRITTEN FOR [213][208][212][201][205][197] BY [206]OEL [206]YMAN
620 [153]"PRINT   (null)N MANY DISKS, YOU'VE SEEN FILES IN
630 PRINT"THE DISK DIRECTORY WITH [211][197][209][153] FOLLOWING
640 [153]"THEIR NAMES.  SYS(null)VAL(null)PRINTUENTIAL FILES ARE OFTEN";
650 [153]"USED BY PROGRAMMERS TO STORE DATA.  tHEY";
660 [153]"CAN ALSO BE USED FOR WORD PROCESSOR AND
670 PRINT"OTHER TEXT FILES.
680 [153]"   (null)E'RE GOING TO SHOW YOU HOW TO MAKE
690 PRINT"YOUR OWN [158][211][197][209][153] FILES TO HOLD DATA FROM
700 [153]"YOUR PROGRAMS, AND HOW TO READ JUST
710 PRINT"ABOUT ANY [158][211][197][209][153] FILE.":GOSUB440
720 PRINT"[147]
730 [153]"LENOMPUTER ASCILES          STR$ISK ASCILES
740 PRINT"[129][163][163][163][163][163][163][163][163][163][163][163][163][163][163]          [163][163][163][163][163][163][163][163][163][163]
750 [153]"LIST10    8    2         1  "Q$"(null)(null)(null)RIGHT$(null)VAL"Q$"     (null)(null)CHR$
760 PRINT" 4    4    0         15 "Q$"[204][197][212][212][197][210]"Q$"     [211][197][209]
770 [153]"15    8   15         12 "Q$"ASC(null)(null)CHR$CHR$RIGHT$VAL"Q$"    (null)(null)CHR$
780 PRINT"[153]   [213]NFORTUNATELY, THE SAME WORD IS OFTEN";
790 PRINT"USED IN THE COMPUTER WORLD TO MEAN TWO
800 [153]"DIFFERENT THINGS.  (null)HE WORD "Q$"FILE"Q$"PRINT HAS
810 PRINT"TWO MEANINGS FOR [195]OMMODORE COMPUTERS.
820 [153]"   (null)OU ALREADY KNOW THAT A COLLECTION OF";
830 [153]"DATA ON A DISKPRINT IS KNOWN AS A SYSFILEPRINT.
840 PRINT"   [212]HE COMPUTER[153] ALSO USES [158]FILES[153], BUT
850 [153]"FOR A DIFFERENT PURPOSE.":[141]440
860 [153]"LOADLIST(null)(null)VAL(null) 4, 4, 0: LEN(null)STR$ 4: (null)RIGHT$(null)(null)PRINT
870 PRINT"   [217]OU MAY HAVE USED COMPUTER FILES
880 [153]"WITHOUT KNOWING IT.  tHE SET OF COMMANDS";
890 [153]"ABOVE (null)RIGHT$(null)(null)PRINTS A PEEKATN(null)RIGHT$LEN PROGRAM TO YOUR":[153]"PRINTER.
900 GOSUB440:SYSQ,1,8:PRINT "^
910 [158]Q,2,6:[153]"DEVICEPRINT":[141]150
920 [153]"(null)HIS IS THE DEVICE NUMBERPRINT. (null)OST
930 PRINT"[195]OMMODORE PRINTERS ARE [158]DEVICE #4[153].
940 [141]440:[158]Q,1,8:[153]"   ^
950 SYSQ,2,3:PRINT"SECONDARY ADDRESS[153]":SYSQ,14,0
960 PRINT"   [212]HIS NUMBER IS CALLED THE SECONDARY
970 [153]"ADDRESSPRINT.  (null)OME DEVICES USE THIS NUMBER
980 PRINT"FOR SPECIAL PURPOSES.  [193] SECONDARY
990 [153]"ADDRESS OF SYSZEROPRINT PUTS LENOMMODORE PRINTERS
1000 PRINT"INTO [213]PPER [195]ASE/[199]RAPHICS MODE.
1010 [141]440:[158]Q,1,5:[153]"^            ^
1020 SYSQ,2,1:PRINT"FILE NUMBER  FILE NUMBER[153]":SYSQ,21,3
1030 PRINT"[212]HIS NUMBER IS THE FILE NUMBER[153].":GOSUB440
1040 PRINT"[147][155][207][208][197][206][153]
1050 [158]59903:[153]"   ATN COMPUTER FILEPRINT IS THE REFERENCE
1060 PRINT"USED BY THE MACHINE AND THE PROGRAMMER
1070 [153]"FOR INPUT/OUTPUT OR SYSRIGHT$/(null)PRINT ACTIVITY.  (null)O
1080 PRINT"COMMUNICATE WITH A PRINTER, MODEM, OR
1090 [153]"DISK DRIVE, YOU MUST CREATE OR (null)(null)VAL(null)PRINT A":[153]"FILE.
1100 PRINT"   [212]HE COMPUTER KEEPS TRACK OF FILES BY
1110 [153]"USING THE FILE NUMBERPRINT.  (null)HIS NUMBER
1120 PRINT"CAN BE ANY WHOLE NUMBER FROM 1[153] THROUGH
1130 [153]"127PRINT.  ((null)HE NUMBERS SYS128PRINT THROUGH SYS255PRINT
1140 PRINT"ARE USED TO ADD AN EXTRA BLANK LINE WHEN";
1150 PRINT"[158][204][201][211][212][153]ING PROGRAMS TO A PRINTER.)
1160 [153]"   (null)OW, ENTER A NUMBER BETWEEN 1PRINT AND
1170 PRINT"127[153] FOR A FILE NUMBER."
1180 PRINT"---> ";:X$=""
1190 LL=3:GOSUB210:XX=VAL(XX$):IF(XX>0)AND(XX<128)GOTO1220
1200 PRINT"[147][153][217]OUR NUMBER SHOULD BE BETWEEN [158]1[153]
1210 [153]"AND SYS127PRINT.   (null)RY AGAIN.":[137]1180
1220 FL$[178]XX$:[153]"LOADLIST(null)(null)VAL(null) "FL$"
1230 PRINT"[153]   [207]NCE WE SET UP OR "Q$"OPEN"Q$"[153] A FILE,
1240 [153]"WE HAVE TO TELL THE COMPUTER WHICH
1250 PRINT"DEVICE WE WANT TO USE WITH THAT FILE.
1260 [153]"   (null)INCE WE'RE GOING TO CREATE A SYS(null)VAL(null)PRINT
1270 PRINT"DISK FILE, WE'LL USE DEVICE #8[153].":GOSUB440
1280 PRINT"[155]"TAB(5+LEN(FL$))",8
1290 [141]150:[153]"PRINTSTR$ON'T FORGET THE SYS"Q$","Q$"PRINT BETWEEN THE
1300 PRINT"FILE NUMBER AND THE DEVICE NUMBER.":GOSUB440
1310 PRINT "[147][155][207][208][197][206] "FL$",8"
1320 PRINT"[147][155][207][208][197][206] "FL$",8":PRINT"[153]   [212]HE [158]SECONDARY ADDRESS[153] YOU NEED TO USE";
1330 PRINT"DEPENDS ON THE DEVICE.  [208]RINTERS AND
1340 [153]"PRINTER INTERFACES USE THE SECONDARY
1350 PRINT"ADDRESS TO CHANGE PRINTING STYLES.
1360 [153]"   STR$ISK DRIVES USE THE SYSSECONDARY ADDRESSPRINT";
1370 [153]"IN THE SAME WAY THAT THE COMPUTER USES
1380 PRINT"FILE NUMBERS.  [198]OR A DISK DRIVE, THE
1390 [153]"SECONDARY ADDRESS IS OFTEN CALLED A":[153]"CHANNELPRINT.
1400 PRINT"   [215]HEN YOU WANT TO [204][207][193][196], [211][193][214][197], READ
1410 [153]"FROM, OR WRITE TO A FILE, THE DISK DRIVE";
1420 [153]"KEEPS TRACK OF WHICH FILE ON THE DISK TO";
1430 [153]"USE BY A CHANNELPRINT NUMBER.":[141]440
1440 [153]"LOAD(null)ET'S REVIEW FOR A MOMENT.
1450 PRINT"[215]HICH ANSWER IS CORRECT?
1460 [153]"   ATN) (null)HE COMPUTER AND THE DISK DRIVE
1470 PRINT"      BOTH USE [158]FILE NUMBERS[153] TO KEEP
1480 [153]"      TRACK OF RIGHT$/(null) INFORMATION.
1490 PRINT"   [194]) [212]HE COMPUTER AND THE DISK DRIVE
1500 [153]"      BOTH USE SYSCHANNEL NUMBERSPRINT TO
1510 PRINT"      KEEP TRACK OF [201]/[207] INFORMATION.
1520 [153]"   LEN) (null)HE COMPUTER USES SYSFILE
1530 PRINT"      NUMBERS[153] AND THE DISK DRIVE
1540 [153]"      USES SYSCHANNEL NUMBERSPRINT.
1550 GETCG$:IFCG$=""GOTO1550
1560 IF(CG$="C")OR(CG$="[195]")GOTO1690
1570 IF(CG$<>"A")AND(CG$<>"[193]")AND(CG$<>"B")AND(CG$<>"[194]")GOTO1550
1580 PRINT"[147][211]ORRY, THAT'S NOT RIGHT.
1590 [153]"(null)HINK OF THE COMPUTER AS A FILING
1600 PRINT"CABINET[153].  [201]MAGINE MANY LITTLE MANILA
1610 [153]"FILE FOLDERS INSIDE THE CABINET, AND
1620 PRINT"EACH ONE HAS ITS OWN [158]NUMBER[153].
1630 [153]"(null)HERE'S A CABLEPRINT  CONNECTING THE DISK
1640 PRINT"DRIVE TO THE COMPUTER, JUST LIKE THE
1650 [153]"CABLE CONNECTED TO A TV SET.  (null)OU
1660 PRINT"SELECT [158]CHANNELS[153] ON THE TV, AND THE[160]
1670 [153]"DISK DRIVE USES SYSCHANNELSPRINT TO KEEP TRACK
1680 PRINT"OF FILES.":GOSUB440:GOTO1440
1690 PRINT"[147][210][201][199][200][212]!":PRINT"[212]HERE ARE SIXTEEN POSSIBLE CHANNELS
1700 [153]"FOR EACH DISK DRIVE.  (null)HEY ARE NUMBERED
1710 PRINT"0[153] THROUGH 15[153].
1720 [153]"   LENHANNEL               (null)URPOSE
1730 PRINT"   [129][163][163][163][163][163][163][163]               [163][163][163][163][163][163][163]
1740 [153]"PRINT      0                  SYS(null)(null)ATNSTR$PRINT ONLY
1750 PRINT"      1                  [158][211][193][214][197][153] ONLY
1760 [153]"      2                   AVAILABLE
1770 PRINT"      3                   AVAILABLE
1780 [153]"      :                   AVAILABLE
1790 PRINT"      :                   AVAILABLE
1800 [153]"     14                   AVAILABLE
1810 PRINT"     15                  [158]COMMANDS[153] ONLY";
1820 PRINT"   [206]OW, PICK A CHANNEL NUMBER TO USE
1830 [158]Q,24,0:[153]"--->        ";:[158]Q,24,5
1840 LL[178]2:[141]210:[139]([197](XX$)[177]1)[175]([197](XX$)[179]15)[137]2010
1850 [139][197](XX$)[177]15[137]1830
1860 [139][197](XX$)[177]0[137]1920
1870 [153]"LOADPRINTLENHANNEL 0PRINT IS USED BY THE SYSSTR$(null)(null)PRINT, (STR$ISK
1880 PRINT"[207]PERATING [211]YSTEM) TO [204][207][193][196] PROGRAMS OR
1890 [153]"THE DISK DIRECTORY INTO THE COMPUTER.
1900 PRINT"[217]OU CAN'T USE IT TO CREATE OR READ":PRINT"[158][211][197][209][153] FILES.
1910 [141]440:[153]"LOAD":[137]1690
1920 [139][197](XX$)[177]1[137]1960
1930 [153]"LOADPRINTLENHANNEL 1PRINT IS USED BY THE SYSSTR$(null)(null)PRINT, (STR$ISK
1940 PRINT"[207]PERATING [211]YSTEM) TO [211][193][214][197] PROGRAMS":PRINT"FROM THE COMPUTER.
1950 [153]"(null)OU CAN'T USE IT TO CREATE OR READ":[153]"SYS(null)VAL(null)PRINT FILES.":[137]1910
1960 [153]"LOADPRINTLENHANNEL 15PRINT IS USED BY THE SYSSTR$(null)(null)PRINT, (STR$ISK
1970 PRINT"[207]PERATING [211]YSTEM) FOR RECEIVING
1980 [153]"COMMANDS AND SENDING INFORMATION
1990 PRINT"ON DISK DRIVE ERRORS TO THE COMPUTER.
2000 [153]"(null)OU CAN'T USE IT TO CREATE OR READ":[153]"SYS(null)VAL(null)PRINT FILES.":[137]1910
2010 SA$[178]XX$:[153]"LOADLIST(null)(null)VAL(null) "FL$",8,"SA$
2020 [153]"PRINT   LEFT$ERE'S WHAT THE SYS(null)(null)VAL(null)PRINT COMMAND LOOKS":[153]"LIKE SO FAR.
2030 PRINT"   [215]E'VE TOLD THE COMPUTER TO [207][208][197][206] FILE
2040 [153]"#"FL$"PRINT AND PLACE IN IT THE FACT THAT
2050 PRINT"WE'RE GOING TO USE CHANNEL #"SA$"[153] ON DISK":PRINT"DEVICE #8[153].
2060 [153]"   (null)EXT, WE NEED A NAME FOR THE DISK
2070 PRINT"FILE WE'RE GOING TO CREATE.":PRINT"[197]NTER A DISK FILE NAME: ";
2080 LL=16:GOSUB200:DF$=XX$
2090 PRINT"[147][155][207][208][197][206]"FL$",8,"SA$","Q$DF$Q$
2100 PRINT"[153]   [212]O GIVE THE DISK DRIVE THE  DISK
2110 [153]"FILE NAME, WE JUST ADD IT TO THE (null)(null)VAL(null)
2120 PRINT"COMMAND.  [196]ON'T FORGET THE [158]"Q$","Q$"[153] AFTER":PRINT"THE SECONDARY ADDRESS.
2130 [153]"   (null)OW WE NEED TO TELL THE DISK DRIVE
2140 PRINT"THAT THIS IS TO BE A SEQUENTIAL FILE.
2150 [141]440:[129]X[178]1029[164]1060:[139][194](X)[178]32[167]P[178]X:X[178]2000
2160 [130]:P[178]P[171]1025:[158]Q,0,P:[153]"SYS,S"Q$
2170 [158]Q,11,3:[153]"PRINT(null)HE SYS,SPRINT TELLS THE DISK DRIVE TO CREATE";
2180 [153]"A SYS(null)VAL(null)PRINTUENTIAL FILE.  (null)OTE THAT THE SYS,S
2190 PRINT"[205][213][211][212][153] BE [201][206][211][201][196][197] THE QUOTE MARKS.
2200 [153]"   (null)EXT, WE HAVE TO TELL THE DISK DRIVE
2210 PRINT"THAT WE WANT TO "Q$"WRITE TO"Q$"[153] THE FILE,
2220 [153]"NOT "Q$"READ FROM"Q$" IT.
2230 GOSUB440:SYSQ,0,P:PRINT"[155],S[158],W"Q$
2240 SYSQ,19,3:PRINT"[153][212]HE [158],W[153] TELLS THE DISK DRIVE TO
2250 [153]"WRITEPRINT TO THE NEW FILE.":[141]440
2260 [153]"LOADPRINT":[153]" THENTAB(TAB(TAB(TAB(TAB(TAB(TAB(TAB(FN       THENTAB(TAB(TAB(TAB(TAB(TAB(TAB(TAB(TAB(TAB(TAB(TAB(TAB(TAB(TAB(TAB(TAB(TAB(TAB(FN
2270 PRINT" [167]  [152][195]PTR[153]  [165]       [167]    [154][196]ISK [196]RIVE[153] ( ) [165]
2280 [153]" THENTOTOTOTOTOTOTOTOFN       THENTOTOTOTOTOTOTOTOTOTOTOTOTOTOTOTOTOTOTOFN
2290 PRINT" [167]        [165]       [167]                   [165]
2300 [153]" THEN   - -  FN       THEN                   FN
2310 PRINT" [167][164][164][164][164][164][164][164][164][165]       [167][164][164][164][164][164][164][164][164][164][164][164][164][164][164][164][164][164][164][164][180]
2320 [153]"   PRINTLEFT$ERE'S WHAT HAPPENS WHEN YOU USE THE":[153]"(null)(null)VAL(null) COMMAND.":[141]440
2330 [153]"LIST(null)(null)VAL(null) "FL$"PRINT
2340 SYSQ,13,3:PRINT"[212]HE COMPUTER LOOKS THROUGH ITS LIST"
2350 PRINT"OF OPEN FILES FOR ONE NAMED [158]"Q$FL$Q$"[153].
2360 [153]"   RIGHT$F IT DOESN'T FIND ONE, IT MAKES ONE.":[141]440
2370 [158]Q,6,5[171][195](FL$):[153]""FL$"PRINT":[141]440
2380 [158]Q,18,3:[153]"RIGHT$F IT FINDS A FILE WITH THAT NUMBER,
2390 PRINT"IT PRINTS [158]"Q$"[198][201][204][197] [207][208][197][206] [197][210][210][207][210]"Q$"[153] AND YOUR
2400 [153]"PEEKATN(null)RIGHT$LEN PROGRAM STOPS.  RIGHT$F YOU TRY TO OPEN";
2410 [153]"MORE THAN 10PRINT FILES, YOU'LL GET A
2420 PRINT"[158]"Q$"[212][207][207] [205][193][206][217] [198][201][204][197][211] [197][210][210][207][210]"Q$"[153].":GOSUB440:GOSUB150
2430 PRINT""TAB(5+LEN(FL$))"[155],8,"SA$"[153]"
2440 GOSUB150:PRINT"[206]EXT, THE DEVICE NUMBER AND THE
2450 [153]"SECONDARY ADDRESS ARE ADDED TO THE FILE":[153]"INFORMATION.
2460 GOSUB440:SYSQ,6,6:PRINT"8"SA$"[153]":GOSUB440
2470 PRINT"[155][207][208][197][206] "FL$",8,"SA$","Q$DF$",S,W"Q$"[153]
2480 [158]Q,14,3:[153]"(null)NCE THE COMPUTER FILE IS OPEN, THE
2490 PRINT"CHANNEL NUMBER AND FILE NAME ARE SENT":PRINT"TO THE DISK DRIVE.":GOSUB440
2500 GOSUB380:SYSQ,5,19:PRINT""SA$"-"DF$
2510 SYSQ,6,25:PRINT"[150]S,W":GOSUB440:PRINT"
2520 [158]Q,18,3:[153]"(null)HE DISK DRIVE CHECKS TO SEE IF A
2530 PRINT"FILE WITH THE SAME NAME IS ALREADY ON
2540 [153]"THE DISK.  RIGHT$T ALSO MAKES SURE THAT THECLOSE
2550 PRINT"CHANNEL IS UNUSED, AND A [158]"Q$"BUFFER"Q$
2560 PRINT"[153]IS AVAILABLE TO HANDLE THE FILE.":GOSUB440:GOSUB150
2570 PRINT"[201]F AN "Q$"ERROR"Q$" OCCURS, THE DISK
2580 [153]"DRIVE ACTIVITY LIGHT BEGINS TO FLASH.":[141]440:[158]Q,13,3
2590 [153]"RIGHT$F THERE'S NO ERROR, THE ACTIVITY
2600 PRINT"LIGHT COMES ON AND STAYS ON TO INDICATE":PRINT"AN OPEN FILE ON THE DRIVE.
2610 [158]Q,3,35:[153]"DEF*":[151]198,0
2620 [141]440:[141]400:[141]390:[141]150
2630 [153]"(null)OW WE'RE READY TO STORE SOME DATA
2640 PRINT"IN THE SEQUENTIAL DISK FILE.  [215]E'LL USE
2650 [153]"THREE STRINGSPRINT OF CHARACTERS.
2660 PRINT"   [197]NTER UP TO 12 ALPHA
2670 [153]"CHARACTERS --->";:LL[178]12:[141]200:A$[178]XX$:[153]
2680 [153]"PRINT   (null)E'LL PUT THIS TEXT IN ATN$PRINT.":[141]440
2690 [141]400:[153]"ATN$="A$:[141]440:[141]150
2700 [158]Q,10,3:[153]"PRINTVALNTER UP TO 12 ALPHA CHARACTERS
2710 PRINT"FOR [194]$[153] --->";:LL=12:GOSUB200:B$=XX$
2720 GOSUB400:PRINT"[194]$="B$:GOSUB440
2730 SYSQ,14,3:PRINT"[153][193]ND LAST, ENTER UP TO 12 CHARACTERS
2740 [153]"FOR LEN$PRINT --->";:LL[178]12:[141]200:C$[178]XX$
2750 [141]400:[153]"LEN$="C$:[141]440:[141]150
2760 [141]400:[153]"(null)(null)RIGHT$(null)(null)#PRINT":[158]Q,10,3
2770 [153]"PRINT(null)O SEND INFORMATION TO THE SEQUENTIAL";
2780 [153]"FILE, WE USE THE SYS(null)(null)RIGHT$(null)(null)#PRINT COMMAND.
2790 PRINT"   [196]O [206][207][212][153] LEAVE A SPACE BETWEEN THE
2800 [153]"SYS(null)(null)RIGHT$(null)(null)PRINT AND THE SYS#PRINT!  RIGHT$T'S ALL ONE "Q$"WORD"Q$".
2810 PRINT"   [201]T WILL BE EASIER TO REMEMBER THIS
2820 [153]"COMMAND IF YOU SAY "Q$"(null)(null)RIGHT$(null)(null) ASCRIGHT$(null)VAL"Q$"PRINT WHEN
2830 PRINT"YOU USE IT, BECAUSE THAT'S WHAT IT DOES.";
2840 PRINT"   [201]T PRINTS[153] TO AN OPEN FILE[153].":GOSUB440
2850 SYSQ,0,0:SYS59903:GOSUB150
2860 PRINT"[198]IRST, WE'LL SEND THE DATA IN [158][193]$[153] TO
2870 [153]"THE SEQUENTIAL FILE.":X[178]500:[141]370
2880 [153]"(null)(null)RIGHT$(null)(null)#"FL$", ATN$":[141]380
2890 [158]Q,5,19:[153]" "A$"PRINT":X[178]1000:[141]370
2900 [158]Q,13,3:[153]"(null)HE DISK DRIVE PLACES "A$
2910 [153]"PRINTIN THE BUFFER IT ASSIGNED TO THE FILE.":[141]440:[141]390
2920 [158]Q,16,3:[153]"(null)EXT, WE'LL SEND THE DATA IN SYSPEEK$PRINT.
2930 PRINT"[208][210][201][206][212]#"FL$", [194]$":GOSUB440:GOSUB380
2940 SYSQ,5,19:PRINT" "B$"[153]":GOSUB440
2950 SYSQ,18,3:PRINT"[212]HE DATA GOES INTO THE SAME BUFFER.
2960 [153]"   ATN SYSLENLEFT$(null)$(13)PRINT (THE CODE FOR SYS<(null)VAL(null)(null)(null)(null)>PRINT) IS";
2970 [153]"PLACED IN THE BUFFER AFTER "A$
2980 [153]"PRINTSEPARATING IT FROM "B$"PRINT.":[141]440:[141]390
2990 [153]"(null)(null)RIGHT$(null)(null)#"FL$", LEN$   PRINT":[141]150
3000 [153]"(null)AST, WE'LL SEND THE DATA IN SYSLEN$PRINT.":[141]440:[141]380
3010 [158]Q,5,19:[153]" "C$"PRINT":[141]440:[141]390:[141]400
3020 [158]Q,12,3:[153]"(null)OW ALL THE DATA HAS BEEN SENT TO
3030 PRINT"THE DISK DRIVE.  [212]HE LAST OF THE DATA
3040 [153]"IS STILL IN THE SYSBUFFERPRINT.  RIGHT$T HASN'T BEEN
3050 PRINT"STORED TO DISK YET.  [215]E CAN SEE THAT,
3060 [153]"BECAUSE THE ACTIVITY LIGHT ON THE DRIVE":[153]"IS STILL LIT.
3070 PRINT"   [212]HE [195][204][207][211][197][153] COMMAND IS USED TO TELL
3080 [153]"THE COMPUTER AND THE DISK DRIVE THAT
3090 PRINT"WE'RE FINISHED WITH THE FILE.":GOSUB440:GOSUB150
3100 PRINT"[195][204][207][211][197] "FL$"[153]":GOSUB380:SYSQ,10,3
3110 PRINT"[193]NY DATA STILL IN THE [158]BUFFER[153] IS":PRINT"WRITTEN TO THE DISK.
3120 [153]"   (null)HEN THAT'S DONE, THE ACTIVITY LIGHT
3130 PRINT"GOES OFF.":GOSUB440:SYSQ,3,35:PRINT" ":GOSUB390:SYSQ,16,3
3140 PRINT"[204]AST, THE COMPUTER [195][204][207][211][197]S[153] THE FILE IN";
3150 PRINT"THE FILE TABLE, FREEING THE SPACE FOR A":PRINT"NEW FILE.":GOSUB440
3160 SYSQ,6,2:PRINT"   - -  ":GOSUB400
3170 SYSQ,19,3:PRINT"[193]ND, WE'RE DONE!":GOSUB440:GOSUB150
3180 PRINT"[217]OU CAN SEND [158]NUMERIC[153] AS WELL AS
3190 [153]"SYSSTRINGPRINT VARIABLES.  ASCOR EXAMPLE:
3200 PRINT"[208][210][201][206][212]#"FL$", [218]     [153](FLOATING POINT)
3210 [153]"(null)(null)RIGHT$(null)(null)#"FL$", (null)%    PRINT(INTEGER)
3220 PRINT"[208][210][201][206][212]#"FL$", "Q$"[200]I"Q$"  [153](LITERAL)":GOSUB440:GOSUB150
3230 PRINT"[212]HE DATA YOU'VE STORED COULD BE NAMES[153]";
3240 PRINT"AND ADDRESSES[153] FOR A DATABASE.  [201]T MIGHT
3250 [153]"BE YOUR DEFLOCATIONPRINT IN A MAZE GAME, SO YOU
3260 PRINT"CAN START FROM THE SAME PLACE AGAIN.
3270 [153]"   (null)R, IT MIGHT BE THE SYSNUMBERSPRINT FROM A
3280 PRINT"CHECKBOOK BALANCING PROGRAM.
3290 [153]"   RIGHT$N ANY CASE, THE DATA IS ONLY USEFUL
3300 PRINT"TO YOU IF YOU CAN [158]READ[153] IT BACK INTO
3310 [153]"YOUR PROGRAM.":[141]440:[141]150
3320 [153]"(null)VALATNSTR$PRINTING A SYS(null)VAL(null)PRINT FILE IS ALMOST THE SAME";
3330 [153]"AS CREATING ONE.
3340 PRINT"   [215]E [207][208][197][206][153] A COMPUTER [158]FILE[153], AND SPECIFY"
3350 PRINT"THE [158]DEVICE[153] AND [158]SECONDARY[153] ADRRESS.":GOSUB440
3360 PRINT"[155][207][208][197][206] "FL$",8,"SA$","Q$DF$Q$"[157][158],S,R"Q$
3370 SYSQ,6,5-LEN(FL$):PRINT""FL$"[153]-8[153]-"SA$:SYSQ,16,3
3380 PRINT"[153][215]E'LL USE THE SAME FILE AND CHANNEL"
3390 PRINT"NUMBERS.  [217]OU COULD USE DIFFERENT ONES.
3400 [153]"   (null)OTICE THAT THIS TIME WE USE A SYS,RPRINT
3410 PRINT"FOR [158][210][197][193][196][153] INSTEAD OF A [158],W[153] AFTER THE":PRINT"FILE NAME.":GOSUB440
3420 GOSUB150:PRINT"[212]HE [207][208][197][206][153] COMMAND CAUSES THE DISK
3430 [153]"DRIVE TO CHECK THE DIRECTORY FOR THE
3440 PRINT"NAMED FILE.  [201]F FOUND, IT [158][207][208][197][206][153]S THE
3450 [153]"FILE FOR SYSREADPRINTING, AND TURNS ON THE
3460 PRINT"ACTIVITY LIGHT.":GOSUB380:SYSQ,5,19:PRINT""SA$"-"DF$:SYSQ,6,25
3470 PRINT"[150]S,R":SYSQ,3,35:PRINT"[150]*":GOSUB440:GOSUB400:PRINT"[201][206][208][213][212]#"FL$",
3480 [141]390:[158]Q,16,3:[153]"PRINT(null)O READ THE DATA, WE USE RIGHT$(null)(null)(null)(null)#PRINT.  ATNS
3490 PRINT"WITH [158][208][210][201][206][212]#[153], THERE'S NO SPACE BETWEEN
3500 [153]"RIGHT$(null)(null)(null)(null)PRINT AND #PRINT.  (null)HINKSYS "Q$"INPUT FILE"Q$"PRINTWHEN
3510 PRINT"YOU USE THE COMMAND.":GOSUB440:PRINT"[201][206][208][213][212]#"FL$", [193]$":GOSUB150
3520 PRINT"[153][212]O READ THE DATA SUCCESSFULLY, YOU
3530 [153]"MUST KNOW THE SYSTYPEPRINT, DEFSEQUENCEPRINT, AND SYSNUMBERPRINT";
3540 [153]"OF VARIABLES STORED IN THE FILE.
3550 PRINT"   [201]F YOU TRY TO READ A [158]STRING[153] INTO
3560 [153]"NUMERIC VARIABLE, SUCH AS ATNPRINT, YOU'LL
3570 PRINT"YOU'LL GET A [150][212][217][208][197] [205][201][211][205][193][212][195][200][153] ERROR FROM
3580 [153]"PEEKATN(null)RIGHT$LEN.":[153]"   (null)INCE WE KNOW THAT WE'VE STORED
3590 PRINT"A [158]STRING[153] AS THE FIRST VARIABLE, WE'LL
3600 [153]"USE ATN$PRINT AS THE VARIABLE NAME FOR THE
3610 PRINT"[158][201][206][208][213][212]#[153] COMMAND.":GOSUB440:GOSUB150
3620 PRINT"[215]HEN THE DISK DRIVE RECEIVES THE
3630 [153]"SYSRIGHT$(null)(null)(null)(null)#PRINT COMMAND, IT READS THE DATA IN THE";
3640 [153]"FILE UP TO THE SYSLENLEFT$(null)$(13)PRINT, AND SENDS
3650 PRINT"IT TO THE COMPUTER.":GOSUB440:GOSUB380:SYSQ,5,19:PRINT""A$:GOSUB420
3660 GOSUB410:PRINT"[201][206][208][213][212]#"FL$", [193]$ [158] <-- [193]$="A$:GOSUB440:GOSUB390:SYSQ,15,3
3670 PRINT"[153][217]OUR PROGRAM CAN NOW USE THE VALUE
3680 [153]"IN ATN$PRINT IN ANY WAY YOU CHOOSE.":[141]440:[141]400:[141]150
3690 [153]"(null)E GET THE TWO REMAINING STRINGS IN
3700 PRINT"THE SAME WAY.  [206]OTE THAT THE [158]NAME[153] OF
3710 [153]"THE VARIABLE DOESN'T MATTER, AS LONG AS
3720 PRINT"THE TYPE[153] IS CORRECT.":GOSUB440:PRINT"[201][206][208][213][212]#"FL$", [216]$":GOSUB380:GOSUB390
3730 SYSQ,5,19:PRINT""B$:GOSUB410:PRINT"[201][206][208][213][212]#"FL$", [216]$ [158] <-- [216]$="B$:GOSUB440
3740 GOSUB400:PRINT"[201][206][208][213][212]#"FL$", [209][209]$":GOSUB380:GOSUB390
3750 SYSQ,5,19:PRINT""C$:GOSUB410:PRINT"[201][206][208][213][212]#"FL$", [209][209]$ [158] <-- [209][209]$="C$:GOSUB440
3760 GOSUB400:GOSUB390:PRINT"[195][204][207][211][197] "FL$:SYSQ,15,3
3770 PRINT"[153][212]HE [158][195][204][207][211][197][153] COMMAND CLOSES THE FILE
3780 [153]"ON THE DISK DRIVE AND REMOVES THE
3790 PRINT"COMPUTER FILE FROM THE FILE TABLE.":GOSUB440:GOSUB380:SYSQ,3,35:PRINT" "
3800 X=500:GOSUB370:GOSUB390:SYSQ,6,2:PRINT"   - -  ":GOSUB400:GOSUB440
3810 GOSUB400:GOSUB150:PRINT"[153][207]NE POSSIBLE PROBLEM WITH USING
3820 [153]"SYSRIGHT$(null)(null)(null)(null)#PRINT IS THE DEFLENGTHPRINT OF STRINGS THAT
3830 PRINT"MAY BE STORED ON THE DISK.  [211]TRINGS CAN
3840 [153]"BE UP TO 255PRINT CHARACTERS LONG.
3850 PRINT"   [217]OU [158]CONCATENATE[153] OR [150]ADD[153] STRINGS
3860 [153]"TOGETHER TO GET LONGER STRINGS.":[153]"(null)$=ATN$+PEEK$+LEN$+STR$$: (null)(null)RIGHT$(null)(null)#"FL$", (null)$
3870 GOSUB440:SYSQ,20,3:PRINT"[153][201]F [158][193]$[153], [158][194]$[153], [158][195]$[153], AND [158][196]$[153] ARE EACH
3880 [153]"60PRINT CHARACTERS LONG, SYS(null)$PRINT WILL HAVE A
3890 PRINT"LENGTH OF [150]240[153]!":GOSUB440:GOSUB150
3900 PRINT"[158][201][206][208][213][212]#[153] HAS A LIMIT OF 80[153] CHARACTERS.
3910 [153]"(null)HAT'S BECAUSE THE COMPUTER READS THE
3920 PRINT"DATA FROM THE DISK INTO THE SAME MEMORY
3930 [153]"AREA THAT'S USED FOR SCREENPRINT INPUT.
3940 PRINT"   [212]HIS MEMORY AREA, OR [158]BUFFER[153] HOLDS
3950 [153]"ONLY 80PRINT CHARACTERS, SINCE THAT'S THE
3955 PRINT"MAXIMUM SIZE OF A [150][195]64[153] SCREEN LINE.
3960 [153]"((null)R 160PRINT CHARACTERS ON A DEFLEN128PRINT).":[141]440:[158]Q,19,3
3970 [153]"(null)O, HOW DO WE SYSREADPRINT A FILE IF WE
3980 PRINT"DON'T KNOW HOW BIG THE STRINGS ARE, OR
3990 [153]"HOW SYSMANYPRINT THERE ARE?":[141]440:[153]"CHR$VAL(null)#"FL$:[141]150
4000 [153]"PRINT(null)E USE THE CHR$VAL(null)#PRINT (SYSGET FILEPRINT) COMMAND.
4010 PRINT"   [201]T'S SIMILAR TO [158][201][206][208][213][212]#[153] BECAUSE IT
4020 [153]"RETRIEVES DATA FROM AN OPEN SYSFILEPRINT.
4030 PRINT"   [201]T'S ALSO SIMILAR TO [150][199][197][212][153], BECAUSE IT
4040 [153]"RETRIEVES ONLY DEFONEPRINT CHARACTER AT A TIME.":[141]440:[141]150
4050 [153]"CHR$VAL(null)#PRINT SHOULD ONLY BE USED WITH A
4060 PRINT"[158]STRING[153] VARIABLE NAME.":PRINT"   [212]O MAKE A [158]STRING[153] IN COMPUTER
4070 [153]"MEMORY USING CHR$VAL(null)#PRINT, YOU HAVE TO DEFASSEMBLEPRINT
4080 PRINT"THE STRING CHARACTER BY CHARACTER.":GOSUB440:GOSUB400
4090 SYSQ,6,5-LEN(FL$):PRINT""FL$"8"SA$
4100 GOSUB150:PRINT"[157][157][157]100 [216][216]$="Q$Q$": [150][210][197][205] [195][204][197][193][210] [216][216]$
4110 [153]"110 CHR$VAL(null)#"FL$", ATN$: (null)=(null)(null)
4120 PRINT"120 [201][198] [193]$="Q$Q$" [212][200][197][206] [193]$=[195][200][210]$(0)
4130 [153]"130 RIGHT$ASC ATN$=LENLEFT$(null)$(13) CHR$(null)(null)(null) 200
4140 PRINT"140 [216][216]$=[216][216]$+[193]$
4150 [153]"150 RIGHT$ASC (null)=0 CHR$(null)(null)(null) 110
4160 PRINT"200 [150][210][197][205] [208][210][207][199][210][193][205] [195][207][206][212][201][206][213][197][211]
4170 [153]"   PRINTLEFT$ERE'S A PROGRAM THAT DEFASSEMBLES
4180 PRINT"[216][216]$[153] FROM A DISK DATA FILE.  [204]ET'S SEE
4190 [153]"HOW IT WORKS.":[141]440:X[178]18:[141]160
4200 [153]"START -->  (null)(null)$="Q$Q$"  SYS(NULL)PRINT":[158]Q,18,3
4210 [153]"   (null)INE 100PRINT CLEARS (null)(null)$PRINT BY MAKING IT
4220 PRINT"[158]NULL[153], EQUAL TO NOTHING."
4230 PRINT"   [212]HEN WE START READING THE INFORMATION";
4240 PRINT"ON THE DISK DRIVE.":SYSQ,5,19:PRINT"[213][208][212][201][205][197][158]R[146]"
4250 SYSQ,6,25:PRINT"[158]^[164][164][195][200][210]$(13)":GOSUB440:X=18:GOSUB160:SYSQ,18,3
4260 PRINT"[212]HE STRING IN THIS DISK FILE IS THE
4270 [153]"NAME (null)(null)(null)RIGHT$(null)VALPRINT FOLLOWED BY THE SYS<(null)VAL(null)(null)(null)(null)>PRINT
4280 PRINT"CHARACTER.":PRINT"   [204]INE 110[153] [150]GET[153]S THE FIRST CHARACTER
4290 [153]"AND PUTS IT IN THE VARIABLE ATN$PRINT.":[141]440:[141]380:[141]420:[141]410
4300 [153]"PASS 1 ->  (null)(null)$="Q$Q$;:[153]"  SYS(ATN$=(null))":[158]Q,5,19:[153]" ":[141]440
4310 [141]420:X[178]18:[141]160:[158]Q,18,3:[153]"PRINT(null)INE 110PRINT ALSO SETS THE VARIABLE SYS(null)"
4320 [153]"PRINTEQUAL TO THE RESERVED VARIABLE SYS(null)(null)PRINT.
4330 PRINT"   [215]E'LL SEE WHAT THAT DOES IN A MOMENT.":GOSUB440:X=18:GOSUB160
4340 SYSQ,18,3:PRINT"[204]INE 120[153] CHECKS FOR A [150]BUG[153] IN THE [158][199][197][212]#[153]";
4350 PRINT"COMMAND.  [201]F THE CHARACTER IN THE FILE
4360 [153]"IS A DEFBINARYPRINT ZERO (NOT THE SYSATN(null)LENRIGHT$RIGHT$PRINT
4370 PRINT"CHARACTER 0[153]), [158][199][197][212]#[153] RETURNS A NULL":PRINT"STRING.":GOSUB440:X=18:GOSUB160
4380 SYSQ,18,3:PRINT"[211]O, WE TEST FOR THE NULL STRING, AND
4390 [153]"IF WE FIND ONE, CHANGE IT TO SYSLENLEFT$(null)$(0)PRINT.":[141]440:X[178]18:[141]160
4400 [158]Q,18,3:[153]"(null)INE 130PRINT CHECKS TO SEE IF WE'RE AT
4410 PRINT"THE END OF THE STRING, [158][193]$=[195][200][210]$(13)[153].  [201]F
4420 [153]"WE ARE, (null)(null)$PRINT IS COMPLETE, AND WE GO ON
4430 PRINT"WITH THE PROGRAM.":GOSUB440:X=18:GOSUB160:SYSQ,18,3
4440 PRINT"[204]INE 140[153] ADDS THE VALUE IN [158][193]$[153] TO
4450 [153]"(null)(null)$PRINT.":[141]440
4460 [153]"PASS 1 ->  (null)(null)$="Q$"(null)"Q$;:[153]"  SYS(ATN$=(null))":[158]Q,5,19:[153]" ":[141]440
4470 X[178]18:[141]160:[158]Q,18,3:[153]"(null)(null)PRINT IS A SPECIAL VARIABLE RESERVED BY
4480 PRINT"[194][193][211][201][195] TO HOLD INFORMATION ABOUT [158][201]/[207][153] OR
4490 [153]"INPUT/OUTPUT ACTIVITY.   (null)HILE WE'RE
4500 PRINT"SUCCESSFULLY READING THROUGH A DISK FILE";
4510 PRINT"[211][212][153] WILL HAVE A VALUE OF [158]ZERO[153].":GOSUB440
4520 X=18:GOSUB160:SYSQ,18,3:PRINT"[193]S SOON AS WE READ THE LAST CHARACTER";
4530 PRINT"IN THE FILE, [211][212][153] CHANGES ITS VALUE TO
4540 [153]"SYS64PRINT.  (null)INE 150PRINT CHECKS VARIABLE (null)PRINT, WHICH
4550 PRINT"WE'VE SET EQUAL TO [211][212][153].  [201]F IT'S STILL
4560 [153]"SYSZEROPRINT, WE'RE NOT AT THE END OF THE FILE.":[141]440:X[178]18:[141]160
4570 [158]Q,18,3:[153]"(null)OW WE'LL SYSCHR$VAL(null)#PRINT THE REST OF THE":[153]"STRING.":[141]440
4580 [131] "(null)","(null)(null)","(null)","(null)(null)(null)","RIGHT$","(null)(null)(null)RIGHT$","(null)","(null)(null)(null)RIGHT$(null)","VAL","(null)(null)(null)RIGHT$(null)VAL"
4590 [129]Z[178]2[164]6:[141]380:[141]420:[141]410
4600 [135]Z$,ZZ$:[153]"PASS"Z"->  (null)(null)$="Q$ZZ$Q$;
4610 [153]"  SYS(ATN$="Z$")":[158]Q,5,18[170]Z:[153]" ":[141]420:X[178]700:[141]370:[130]
4620 [141]380:[141]420
4630 [141]410:[153]"PASS 7 ->  (null)(null)$="Q$ZZ$Q$;:[153]"  SYS(ATN$=LENLEFT$(null)$(13))":[141]390:[141]440
4640 [141]400:[141]150:[153]"(null)OU CAN USE SYSCHR$VAL(null)#PRINT AND SYS(null)(null)PRINT TO READ AND
4650 PRINT"PRINT TO THE SCREEN ANY SEQUENTIAL FILE:":PRINT"250 [199][197][212]#101,[193]$
4660 [153]"260 (null)(null)RIGHT$(null)(null) ATN$;  PRINT<--DON'T FORGET THE SYS;
4670 PRINT"270 [201][198] [211][212]=0 [199][207][212][207] 250":GOSUB440
4680 PRINT"[147][153]   [211]O FAR WE'VE ASSUMED THAT THERE WERE
4690 [153]"NO SYSDISK ERRORSPRINT AS WE WORKED WITH FILES.
4700 PRINT"   [201]N THE REAL WORLD, THINGS WON'T BE
4710 [153]"QUITE SO ERROR FREE.  (null)OU MAY GET A
4720 PRINT"[158][198][201][204][197] [206][207][212] [198][207][213][206][196][153] OR [158][196][210][201][214][197] [206][207][212] [210][197][193][196][217][153]
4730 [153]"ERROR.":[153]"   (null)HE DISK DRIVE SENDS ERROR MESSAGES
4740 PRINT"IN THIS FORMAT:":PRINT"62  [198][201][204][197] [206][207][212] [198][207][213][206][196]  18  00"
4750 PRINT "[153]   [212]HE [158]"Q$"62"Q$"[153] IS THE [150]ERROR NUMBER[153].  [217]OU'LL";
4760 PRINT"FIND THE POSSIBLE ERROR NUMBERS LISTED
4770 [153]"IN YOUR DISK DRIVE MANUAL.  (null)HE NUMBER
4780 PRINT"IS FOLLOWED BY A [158]STRING[153] THAT DESCRIBES
4790 [153]"THE ERROR.":[153]"   (null)HE LAST TWO NUMBERS ARE THE TRACK
4800 PRINT"AND SECTOR NUMBERS WHERE THE [158]ERROR[153]
4810 [153]"OCCURED.":[141]440:[153]"LOAD   (null)OU SHOULD ALWAYS CHECK FOR ERRORS
4820 PRINT"WHEN WORKING WITH DISK FILES.  [212]O DO
4830 [153]"THAT, SYS(null)(null)VAL(null)PRINT A FILE TO THE SYSCOMMAND
4840 PRINT"CHANNEL[153] ON THE DISK DRIVE [194][197][198][207][210][197][153] YOU
4850 [153]"(null)(null)VAL(null) DEFANYPRINT OTHER FILES!":[153]"100 (null)(null)VAL(null) 15,8,15
4860 PRINT"[153]   [208]ROGRAMMERS USUALLY USE [158]COMPUTER
4870 [153]"FILE #15PRINT.  (null)OU MUSTPRINT USE SYSDISK CHANNEL
4880 PRINT"#15[153], THE COMMAND CHANNEL.":PRINT"   [212]HEN, AFTER YOU [207][208][197][206] A FILE, READ
4890 [153]"THE COMMAND CHANNEL:":[153]"150 RIGHT$(null)(null)(null)(null)#15, (null), (null)$"
4900 [153]"160 RIGHT$ASC (null)>19 (null)LEFT$VAL(null) (null)(null)RIGHT$(null)(null) (null)$: LEN(null)(null)(null)VAL15: VAL(null)STR$":[141]440:[158]Q,18,3
4910 [153]"STR$ISK ERRORS START WITH SYS20PRINT, SO ANY
4920 PRINT"NUMBER LESS THAN [158]20[153] MEANS IT'S ALL
4930 [153]"RIGHT TO CONTINUE.  (null)HEN YOU END YOUR
4940 PRINT"PROGRAM, [158][195][204][207][211][197] 15[153] LAST, SINCE CLOSING
4950 [153]"THE COMMAND CHANNEL CLOSES ALL OTHERS.":[141]440
4960 [153]"LOAD   (null)E'VE JUST HINTED AT THE THINGS YOU
4970 PRINT"CAN DO CREATING AND READING DISK FILES.
4980 [153]"   (null)N THIS SYS(null)P(null)IMEPRINT DISK, YOU'LL FIND
4990 PRINT"[198][201][204][197] [210][197][193][196][197][210][153], WHICH USES THE TECHNIQUES
5000 [153]"WE'VE LOOKED AT HERE.  (null)OU CAN DEF(null)RIGHT$(null)(null)PRINT AND
5010 PRINT"CHANGE IT TO SUIT YOUR NEEDS.":PRINT"   [201]F YOU'D LIKE TO LEARN MORE ABOUT
5020 [153]"CREATING AND USING DISK FILES, LOOK FOR
5030 PRINT"     1541 [213][211][197][210]'[211] [199][213][201][196][197]":PRINT"       BY [196]R. [199]ERALD [206]EUFELD":PRINT"      ([194]RADY)
5040 [153]"PRINT   (null)HE BOOK SHOULD BE AVAILABLE THROUGH
5050 PRINT"ANY MAJOR BOOKSTORE.":PRINT"   [215]E HOPE YOU'VE HAD FUN SEEING HOW TO
5060 [153]"MAKE SYSDISK FILESPRINT WORK FOR YOU!":[158]Q,23,3
5070 [153]"LIST (null)RESS ATN(null)(null) KEY TO RETURN TO (null)P(null)IME ":[146]198,1:[137]490