Apple Orchard 1980 Fall v1n2 reduced

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PAGE 56 the ASCII chart in them, usually in an appendix . We strongly recommend that you check out your own computer's ASCII. NUMBER, PAH-LEEZ. If line 300 had called for an address usually beginning with a number then we could use the same basic format as line 680 changing the parameter values to reflect "O" as the lowest acceptable input and "9" as the highest: IF LEFT$ (IN$,1) => "O" AND LEFT$ (IN$, 1) = < "9" THEN GOTO NEXTPHRASE Naturally, you'd .change the subroutine to reflect that what's wanted is a number rather than a letter. It's easy to include exceptions in the line. Let's say that the address could begin with the word BOX, as in a post office box: IF LEFT$ (IN$, 3) = "BOX" OR (LEFT$ (IN$,1) = >"O" AND LEFT$ (IN$, 1) = "15" THEN GOTO REJECT The same format can be used for any range of individual characters or strings. The observant reader (you clever person, you!) will note that even in those cases where we want a number we use a string input. There are two basic reasons for this apparantly cavalier use of strings. First, strings are easier to manipulate. LEFT$-RIGHT$-MID$ functions don't work on integers and reals, and these string functions are the most convenient ones in BASIC to use for error trapping. And secondly, many BASICs will give a HARD rejection FALL <strong>1980</strong> if a non-numeric character is entered when a numeric variable is used to accept an input. That means, friend, that your program might crash and burn. A string variable, on the other hand, usually will accept anything. LEADING/TRAILING SPACES There is a negative side to this lack of discrimination on the part of string variables. Since they accept whatever is typed, they will accept inadvertant hits of the space bar. The string "gobble" is NOT the same as the string" gobble". When the computer looks at "gobble" the first thing it sees after the quote mark is ASCII 71 - what we see as a G. But when it looks at " gobble" the first thing it sees is ASCII 32, the space. That means that the name " Martha Mayno" will NEVER be found in a data base searching for "Martha Mayno". Goodness knows we don't want to lose poor Martha! Since the example we've been using is supposed to be part of a name and address data base, we're concerned about extraneous spaces. So we'll add the following lines: 710 IF LEFT$ (IN$, 1) < > " "THEN 740 720 IN$= RIGHT$ (IN$, LEN (IN$) - 1 ) 730 GOTO 710 This code eliminates leading spaces from a string. It keeps on looping until all leading spaces are gone (just in case more than one got in). You'll also want to check for trailing spaces (since "Martha Mayno "will be lost forever) which can be done using similar code. The only real change is the substituting of BASIC's RIGHT$ function for LEFT$ (which works the same way, except backwards - see your BASIC manual for details). The following two lines of code are based on the way APPLESOFT handles the "truth" of IF-THEN statements: if the condition is false the program goes to the next line, as opposed to the next statement. Thus we can write: 710 IF LEFT$(1N$, 1) =""THEN IN$ = RIGHT$ (IN$, LEN (IN$) - 1 ) :GOTO 710 720 IF RIGHT$ (IN$, 1) =""THEN IN$ = LEFT$ (IN$, LEN (IN$) - 1): GOTO 720
ALL <strong>1980</strong> THE APPLE ORCHARD PAGE 57 We keep on Looping in lines 710 and 720 until all leading and trailing spaces are gone, just in case the space bar got hit more than once. These new lines are different from the other "error checkers" we have seen in that they automatically correct the error rather than making the user do it. Here's the Program in its final form : 100 VTAB 10 200 HTAB 1 300 PRINT "NAME: ................... .
Page 1 and 2:
IN THIS ISSUE. APPLElll . IS HERE!
Page 3 and 4:
When It Comes To APPLE Add-on Memor
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FALL 1980 THE APPLE ORCHARD PAGE 3
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Page 11 and 12: FALL 1980 screen has even more than
Page 15 and 16: FALL 1980 THE A PPLE ORCHA RD PAGE
Page 33 and 34: FALL 1980 from the interrupt routin
Page 35 and 36: FALL 1980 An antenna is simply a de
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Page 40 and 41: PAGE 38 THE APPLE ORCHARD FALL 1980
Page 42 and 43: PAGE 40 -123456 will take 3 words:
Page 44 and 45: PAGE 42 THE APPLE ORCHARD AUTO-RUN
Page 46 and 47: PAGE 44 AUTO-RUN LISTING from page
Page 50 and 51: In the Business World of the 1880's
Page 52 and 53: Find Your Way Aro und The New Apple
Page 64 and 65: ' fnsaZ430 pr ttie Apple's 6502 and
Page 66 and 67: INTBlf0ACTIV& VIBO •Education •
Page 68 and 69: PAGE 66 THE APPLE ORCHARD INFLATION
Page 70 and 71: PAGE 68 erals, the system could be
Page 72 and 73: MR. RA\NBO~nounces our all new 1980
Page 74 and 75: BELL & HOWELL SERVICE CAN GET TO TH
Page 76: Mountain Hardware Leadership in Com
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Apple Orchard 1980 Fall v1n2 reduced

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