Introduction



This book contains 35 BASICprograms for thecorect. If the numbers are diferent, you need
Commodore 64,each with easy-to-folow direc-to carefuly check your line against ours, and
tions, a complete program listing, notes aboutcorect the eror. Youmay have misunderstood
important variables, and an outline of how theour listing notation (did you forget to hold
program works. Youdon't need to know how todown the SHIFT or COMMODORE keys?). Other
program the Commodore 64 to use this book-common mistakes include using the leter "I"
just type the programinto your computer,(el) instead of the number "1," the leter "0"
SAVEit on disk or casete tape, and then type(oh) rather than "a" (zero), or typing the wrong
RUN. If you already know BASIC,the informa-number of characters.
tion about importantvariables and how thePROOF-IThelps you type programs from this
programs work wil help you understand howbook that work the first time. It catches almost
to modify the programs.altypingmistakes,includingtransposed
Our PROOF-IT proofreading program helpscharacters,such as "XT" when you meant
you avoid typing erors. With PROOF-IT, you"TX." PROOF-ITchecks on "important" spaces
avoidthe frustrating"debugging"neededinsidequotesbutignores"unimportant"
when typing erors keep programs from work-spaces outside ofquotes. It even lets you use the
ing right. Another helpful feature is the specialhandy"shorthand"of BASIC keywordab-
notation used in the program listings. The no-breviations, so you can type a question mark
tation shows each key you need to press, andinstead of the keyword "PRINT."
gives a count for repeated strings ofcharacters.
Commodore charactergraphics are hard to
read with "normal" listings on a CommodoreGetingStartedwith PROOF-IT
printer.Finaly,al programs(except the
"QUICK" series) are identical from line 600001. Type NEW.
on.This"standardframework"handles2. Type PROOF-IT exactly as shown. Be careful
keyboardinput, joystick manipulation,theto include blanks, since they are important.
title screen, checking for3. SAVEthe program on disk or tape. Warning:
Q to quit, and reset-
ting the C-64 to standard colors, among otheryou'l lose PROOF-IT if you do not SAVE it
now!
things. The standard framework saves lots of
typing, since you type it only once (using4. TypeRUN. The copyright notice wil appear,
PROOF-IT to make sure it's corect), SAVE itthen the mesage" SETTING UP" folowed
on disk or tape, and then LOADit before typingby a series of dots.
a program from the book.5.If everything is corect, the C-64 wil print
"READY." When you type a BASIC line and
press RETURN, the proof number wil appear
THE PROOF-IT PROOFREADERin the upper left-hand corner of your screen
in reverse video.
PROOF-IT is a powerful proofreading program
that helps you avoid typing mistakes. As youPROOF-IT is great, but before you can use it
type each line of a program, PROOF-IT calcu-you must type it into your C-64.Unfortunately,
lates a "proof number" which it displays at theyou won't have a smart program(such as
top ofthe C-64screen when you press RETURN.PROOF-IT) to help you locate and corect typ-
At the end of each program line in the listings,Ing erors.
we print the corect proof number for that line.Tohelp solve this" geting started" problem,
If the number PROOF-IT shows matches thePROOF-ITchecks itselfour diferent ways, and
number in the book, the line you just typed isprints an eror message and stops if it finds

