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T R U E B A S I C The Structured Language System For The Future INSTRUCTIONS COMMODORE AMIGA 512K VERSION 1 PRINTED BY COL (NOVA U.K. 1988). CREDITS Amiga A500 Pye Studiocolour TV Amstrad DMP2000 Printer Cumana External Drive Wordperfect V4.1 Nescafe Coffee Benson & Hedges These instructions have been taken from the two manuals that come with the True BASIC program disk. All essential details have been included. For a clearer idea of how some of the commands operate please examine the demo basic programs on the system disk, as these have all been taken from the original manuals and were used to accompany the text. WRITING PROGRAMS The LET statement assignes values to variables. The values may be written as constants, variables, or expressions. Unlike some other BASICs, LET is a mandatory keyword in True BASIC. LET statements have the form: LET variable = expression The Print statement displays the results of a program on your screen. You can print constants, variables, and expressions. PRINT statements have the form: PRINT expression1, expression2 The last statement in each True BASIC program must be an END statement. The END statement is simply: END Program Listing "MPG" LET miles = 320 LET gallons = 14.3 PRINT miles, gallons, miles/gallons END Constants are quantities whose values cannot change. Constants may be whole numbers or decimals. True BASIC does not allow commas or spaces inside constants. Variables are quantities whose values may change. Variable names may be up to 31 characters long. Names must begin with a letter, but subsequent characters can be letters, digits, or the underscore character. Expressions may be any combination of variables, constants, and operators. In True BASIC, multiplication and division have higher priority then addition and subtraction. Exponentiation has highest priority. MODIFYING PROGRAMS Choose Show Output from the Windows menu to activate the Output Window. You can scroll a line horizontally by clicking at the very end of that line, or by using the cursor keys. The Tab key moves the insertion point to the next word on thecurrent line. If there isn`t one, it moves underneath the next word on the previous line. You can select text by dragging, or you can select a word by double-clicking and an entire line by triple-clicking. You can delete selected text by choosing Cut from the Edit menu, by pressing Command-X, or by pressing backspace or del. An exclamation point signals the beginning of a comment in True BASIC. Comments can occupy whole lines, or they may be on the same line as an executable statement. The INPUT statement allows you to enter variables values from the keyboard while the program is running. INPUT statements have the form: INPUT variable1, variable2, ... True BASIC displays error messages in the bar at the bottom of the source window, and simultaneously moves the insertion point to the line which contains the error. The SAVE command saves your program on the disk under it`s current name. The SAVE AS command also saves your current program on the disk, but asks you to provide a new name for it. The UNSAVE command deletes a file from the disk. Give the UNSAVE command by choosing Unsave from the Project menu. ELEMENTARY STRINGS True BASIC uses "strings" to represent text and other items which do not necessarily have numeric values. A string constant is any sequence of characters enclosed in double quotes. The characters in the string may include numbers, letters, punctuation marks, or other special characters. String variables are names for string values. The names of string variables must end in a dollar sign ($) to distinguish them from numeric variable names. When a PRINT statement has more than one item on it, True BASIC uses print zones, or columns, 16 characters wide, if the items are separated by commas. If the items are separated by semicolons, True BASIC displays strings with no leading or trailing spaces, and numbers with a space on each side. INPUT statements can include a prompt, and can process more than one item. The formats are: INPUT variable INPUT variable1, variable2, ... INPUT PROMPT expression$: variable1, variable2, ... The command NEW tells True BASIC to clear the editing window (and memory) to make room for a new program. LINE INPUT statements allow you to enter any kind of reply, even nothing. They have the form: LINE INPUT variable$ LOOPS AND PRINTERS The FOR-NEXT loop is a True BASIC structure that allows you to repeat a block of statements a specified number of times. The loop is governed by an index variable, whose value changes each time the loop is executed. The FOR statement defines the starting value and ending value of the index variable. The NEXT statement indicates the end of the loop structure. FOR variable = first TO last - - - - - - block of statements - - - NEXT variable If no step is given in the FOR statement, the index variable is incremented by one each time the loop is repeated. By including a step size in the FOR statement, you can choose other increments for the index variable. FOR variable = first TO last STEP size - - - - - - block of statements - - - NEXT variable Example Program ! Square roots. ! PRINT "Number", "Square Root" ! Print labels PRINT ! Leave blank line FOR number = 0 to 1 step .1 ! Go from 0 to 1 in small steps PRINT number, Sqr(number) ! Print number and square root NEXT number END You can even make the value of the index variable decrease each time the loop is executed by specifying a negative step size. True BASIC has several built-in functions which take input values from the program that uses them and returns a single value to the program. The input values, and the value returned, may be either string or numeric. The block of statements within a loop may include any True BASIC statement, even another control structure. To use your printer, first open a channel to the printer. Then use this channel in PRINT statements. OPEN #expression: PRINTER PRINT #expression: expression, expression, ... PRINT #expression: expression; expression; ... Example Program ! Print pattern of x's. ! FOR row = 1 to 6 FOR xcount = 1 to row PRINT "x"; NEXT xcount PRINT NEXT row END IF-THEN, RANDOMIZE AND STOP The IF-THEN structure allows you to modify the flow of control in a program by telling True BASIC to execute a statement or block of statements only if a condition is true. If only one statement is to be executed when the condition is true, you can write the entire IF-THEN structure on one line IF condition THEN statement IF-THEN structures use "comparisons" to make their decisions. Comaparisons chack values against other values by useing relational operators. True BASIC`s relational operators are: Operator Meaning = equal to <> or >< not equal to < less then <= or =< less than or equal to > greater than => or >= greater then or equel to These operators work on all combinations of constants, variables, and expressions. To execute more then one statement if the condition is true, you need to use a multiple-line IF-THEN structure. You must use an END IF statement to signal the end of the structure. IF condition THEN - - - - - - block of statements - - - END IF By using and ELSE statement, you can specify what actions to take if the condition is false. IF condition THEN statement1 ELSE statement2 In a multiple-line structure, the ELSE statement must be on a line all by itself. The statements between the IF-THEN statement and the ELSE statement will be executed if the condition is true, and the statements between the ELSE statement and the END IF statement will be executed if the condition is false. IF condition THEN - - - - - - block of statements - - - ELSE - - - - - - block of statements - - - END IF The RANDOMIZE statement scrambles the sequence of random numbers returned by the Rnd function. The STOP statement stops a running program. Example Program ! Flip a coin five times. ! FOR toss = 1 to 5 IF Rnd<.5 then PRINT "Heads, you win" NEXT toss END Example Program ! Program to play a guessing game. ! RANDOMIZE LET answer = Int(Rnd*6) + 1 ! Choose number from 1 to 6 PRINT "I'm thinking of a number from 1 to 6." PRINT "You have 3 chances to guess it." PRINT FOR chance = 1 to 3 PRINT "Enter your guess"; ! Ask for number INPUT guess IF guess = answer THEN PRINT "Correct!!!" STOP ! Stop here, you guessed it END IF NEXT chance PRINT PRINT "The number was"; answer END Example Program ! Program to play a guessing game. ! RANDOMIZE LET answer = Int(Rnd*6) + 1 ! From 1 to 6 PRINT "I'm thinking of a number from 1 to 6." PRINT "You have 3 chances to guess it." PRINT FOR chance = 1 TO 3 PRINT "Enter your guess"; ! Ask for number INPUT guess ! Get a guess IF guess < 1 THEN ! Check it out PRINT "Must be at least 1." ELSE IF guess > 6 then PRINT "Can't be more than 6." ELSE IF guess < answer then PRINT "Too low." ELSE IF guess > answer then PRINT "Too high." ELSE ! Must be right PRINT "Correct!!!" STOP END IF END IF END IF END IF NEXT chance PRINT "The number was"; answer; "." END DO LOOPS A DO loop lets you execute blocks of statements repeatedly. DO loops differ from FOR-NEXT loops in that you don`t specify ahead of time just how many times the statements inside the loop will be repeated. Instead, the number of times depends on the result of logical comparisons made while the program is running. You can specify when the DO loop stops by a condition in either the DO statement at the beginning of the loop, the LOOP statement at the end of the loop, or both. You can specify that the loop will be repeated WHILE a certain condition remains true, or UNTIL a certain condition becomes true. DO UNTIL condition - - - - - - block of statements - - - LOOP DO WHILE condition - - - - - - block of statements - - - LOOP DO - - - - - - block of statements - - - LOOP UNTIL condition DO - - - - - - block of statements - - - LOOP WHILE condition The rules for conditions in DO loops are the same as in IF-THEN statements: you can use constants, variables, and expressions with relational operators. You can create combinations of conditions with the logical operators AND, OR, and NOT. Example Program ! Program to compute interest on a bank account. ! Stop when the money has doubled. ! LET money = 10000 ! Start with $10,000 LET original = money ! Remember original amount LET interest = 8.5/100 ! Interest is 8.5% DO until money >= 2 * original ! Loop until money doubles PRINT years, money ! Print year and money LET years = years + 1 ! Keep track of how long LET money = money + (interest * money) ! Add in interest LOOP PRINT "In"; years ; "years, you'll have $"; money END STORING DATA VALUES DATA statements store values that can be assigned to variables. Their format is: DATA item1, item2, ... READ statements assign data values to variables. Their format is: READ variable1, variable2, ... The variables in a READ statement may be numeric, string, or an assortment of the two. True BASIC will give you an error message if you try to read a non-numeric data value into a numeric variable, but will not if you read a number into a string variable. You can use True BASIC`s built-in conditions, MORE DATA and END DATA, in a DO loop to see whether there are any more data to be read. The RESTORE statement restores all your program`s data. The next READ statement will read the first item from the list of data statements. Example Program ! Trivia quiz. ! READ num_quest ! Number of questions FOR i = 1 to num_quest ! Read all questions READ question$, answer$ PRINT question$; LINE INPUT reply$ ! Get user's guess IF reply$ = answer$ THEN ! If correct... LET right = right + 1 ! Count right replies PRINT "Correct." ! And say bravo ELSE PRINT "No, the correct answer is "; answer$; "." END IF NEXT i PRINT "You got"; 100 * right/num_quest; "% right." DATA 5 DATA What is the capital of Austria, Vienna DATA What year did Franklin Pierce take office, 1853 DATA "What is the capital of Manitoba, Canada", Winnipeg DATA "How many years, on average, does a baboon live", 20 DATA How about a gray squirrel, 5 END INTRODUCTION TO GRAPHICS The PLOT statement draws points and lines on your screen. You describe the points in terms of coordinates, which are pairs of numbers. Each pair of numbers defines a particular location on the screen. PLOT statements have the forms: PLOT x,y PLOT x,y,; PLOT x1,y1; x2,y2; ... The first draws a single point. The semicolons in the second and third forms tell True BASIC to "leave the beam on" between points, thereby drawing lines. You can make a program stop at any time during its execution by choosing Stop from the Run menu, or pressing Command-period. The SET WINDOW statement lets you define the boundaries of your screen in terms of your own coordinates. SET WINDOW left, right, bottom, top Any points, lines, or text outside those boundaries won`t be visible. You can use the PLOT TEXT statement to add text to your graphic output: PLOT TEXT, AT x,y: "label" The CLEAR statement clears the output window (or full screen). It`s form is simply: CLEAR The PAUSE statement suspends program execution for a specified number of seconds: PAUSE seconds You can also "freeze" your program by choosing Pause from the Run Menu, or by pressing Command-W. A program suspended in this manner will resume as soon as you click or press a key. True BASIC normally uses radians when it calculates angles, sines, cosines, etc. To use degrees instead, add an OPTION statement to your program: OPTION ANGLE DEGREES The OPTION statement should precede any executable statement which would otherwise use radians. Example Program ! Plot random points. ! DO LET x = Rnd ! Pick two random numbers LET y = Rnd PLOT x,y ! Plot a point there LOOP END Example program ! Plot number of cars sold from 1900 to 1980. ! SET WINDOW 1900, 1980, 0, 10e6 FOR year = 1900 to 1980 step 10 ! Years by decades READ cars ! Read number of cars PLOT year, cars; ! Plot to this point NEXT year ! Car production data. DATA 4190, 187e3, 2.2e6, 3.3e6, 4.4e6, 8.0e6, 7.8e6 DATA 8.2e6, 8.0e6 END Example Program ! Plot number of cars sold from 1900 to 1980. ! SET WINDOW 1900, 1980, 0, 10e6 FOR year = 1900 to 1980 step 10 ! Years by decades READ cars ! Read number of cars PLOT year, cars; ! Plot to this point NEXT year PLOT SET WINDOW 1900, 1980, 0, 250e6 FOR year = 1900 to 1980 step 10 ! Years by decades READ pop ! Read population PLOT year, pop; NEXT year ! Car production data. DATA 4190, 187e3, 2.2e6, 3.3e6, 4.4e6, 8.0e6, 7.8e6 DATA 8.2e6, 8.0e6 ! Population data. DATA 76e6, 92e6, 105.7e6, 122.8e6, 131.7e6 DATA 150.7e6, 179.3e6, 203.3e6, 226.5e6 END Example Program ! Lissajous experiment ! SET WINDOW -1, 1, -1, 1 DO PRINT "X multiplier, Y multiplier"; INPUT xmult, ymult CLEAR FOR i = 0 to 2*pi STEP pi/100 ! Draw the figure PLOT sin(xmult*i), cos(ymult*i); NEXT i PLOT ! Turn off the beam PAUSE 3 ! Wait 3 seconds CLEAR ! Then clear the screen LOOP END ADVANCED GRAPHICS True BASIC has a family of graphics statements, the BOX statement, which performs fast operations on rectangular areas of the screen: BOX AREA left, right, bottom, top BOX CIRCLE left, right, bottom, top or BOX ELLIPSE left, right, bottom, top BOX CLEAR left, right, bottom, top BOX KEEP left, right, bottom, top IN variable$ BOX LINES left, right, bottom, top BOX SHOW variable$ AT left, bottom BOX SHOW variable$ AT left, bottom USING "and" BOX SHOW variable$ AT left, bottom USING "or" BOX SHOW variable$ AT left, bottom USING "xor" The SET COLOR statement sets the foreground colour for all graphic ouput. SET COLOR can be used with either a number or a name. The Workbench screen has three foreground colours which are controlled by the Preferences tool. The FLOOD statement fills a shape with the current colour. It`s form is: FLOOD x, y The SET BACK statement changes the background colour. It uses the same colours as SET COLOR. The SET COLOR MIX statement changes the shade of some colour number. You must specify the colour number to change, and the new settings for the red, green, and blue colour guns. The Amiga`s "HIGH 16" mode provides high-resolution, full screen graphics with 16 colours. Name Number in HIGH16 mode Backgound 0 White 1 Blue 2 Red 3 Yellow 4 Black 5 Green 6 Cyan 7 magenta 11 Brown 13 True BASIC lets you specify colours by name, as well as by number. True BASIC uses the GET POINT and GET MOUSE statements for graphic input: GET POINT x, y GET MOUSE x, y, state GET POINT returns the X- and Y-coordinates of the point where you click. GET MOUSE returns the current coordinates and state of the mouse. The mouse states are: Number State 0 Button up 1 Button down 2 Button clicked 3 Button released True BASIC uses channel numbers to identify a particular source for input of destination for output. For example, to specify a separate window for graphic output, you must first open a channelto that portion of your screen. This OPEN statement has the form: OPEN #expr: SCREEN left, right, bottom, top You may have as many as ten channels open at a time, but only one window is active. All output goes to the active window. To make a window active, use: WINDOW #expr Example Program ! Draw a box. ! SET WINDOW -14, 14, -10, 10 ! 0,0 is center of window BOX LINES -5, 5, -5, 5 ! 5*2 is length of each side END Example Program ! Draw a circle picture. ! PICTURE Circle(sides) FOR i = 0 to sides LET u = (i*2*Pi)/sides ! Find next angle PLOT Cos(u), Sin(u); ! Plot next segment NEXT i PLOT ! Turn off beam END PICTURE SET WINDOW -15, 15, -10, 10 ! Set the window FOR j = 1 to 30 ! Draw a bunch of circles DRAW Circle(j) with Scale(j/3) ! Bigger and better NEXT j END Example Program ! A bouncing ball. ! SET WINDOW 0, 30, 0, 20 LET delta = +1 ! +1 is up, -1 is down LET x = 15 ! Start in center LET y = 10 BOX CIRCLE x, x+1, y, y+1 ! Show first ball FLOOD x+.5, y+.5 ! Fill in circle BOX KEEP x, x+1, y, y+1 in ball$ ! Remember that image DO BOX CLEAR x, x+2, y, y+2 ! Erase old ball LET y = y + delta ! Continue on course IF y < 1 OR y > 19 then LET delta = -delta BOX SHOW ball$ at x,y ! Draw new ball PAUSE .05 ! Not too fast LOOP END Example Program ! Program to illustrate use of "xor". ! SET window 0, 10, 0, 10 BOX AREA 0, 1.5, 0, 1.5 ! Draw a rectangle BOX KEEP 0, 1.5, 0, 1.5 in box$ ! and keep it BOX CLEAR 0, 1.5, 0, 1.5 FOR i = 1 to 8 ! Show overlapping boxes BOX SHOW box$ at i, i using "xor" NEXT i END Example Program ! Show the Amiga's "HIGH16" mode. ! SET mode "HIGH16" SET window 0, 16, 0, 1 FOR x = 0 to 15 SET color x BOX AREA x, x+1, 0, 1 NEXT x END Example Program ! Draw circles and ellipses. ! DO GET POINT x1, y1 ! Choose one point GET POINT x2, y2 ! Choose another point BOX CIRCLE x1, x2, y1, y2 ! Draw circle LOOP END MUSIC AND SOUND EFFECTS The PLAY statement lets you play simple melodies on your computer. You can specify the notes to be played, the length of each note, and the tempo of the music. PLAY statements have theform: PLAY music$ The string expression in the PLAY statement consists of music codes. Some of True BASIC`s music codes are: Code Meaning A to G Play a note in current octave L n Set the length of subsequent notes ML Play music legato, or smoothly MN Play music normally MS Play music staccato, or briskly O n Set current octave. Middle C is the first not in octave 5 R n or P Rest for length n T n Set the tempo # or + Sharp - Flat . Play dotted note The SOUND statement lets you use your computer`s speaker to produce sounds of specified frequency and duration: SOUND frequency, duration The frequency is measured in Hertz (cycles per second) and the duration in seconds. Example Program ! Plays the beginning of ! "On Top of Old Smoky". ! DO while more data READ music$ ! Get the string representations PLAY music$ ! And play the notes LOOP DATA O4 L4 C C E G O5 L2 C. O4 A. DATA L4 A F G A L1 G DATA L4 C C E G L2 G. D. DATA L4 E F E D L2 C. END Example Program ! Imitate ringing of a telephone. ! FOR ring = 1 to 8 ! Let ring 8 times FOR i = 1 to 30 ! Each ring = 30 alternations SOUND 600, .03 ! Freq 600 for .03 sec SOUND 1500, .03 ! Then 1500 for .03 sec NEXT i PAUSE 2 NEXT ring END ADVANCED EDITING The Search menu has three commands for finding and changing words (or numbers, or parts thereof) in your program: The Search Menu Move to block... Move the insertion point to specified line Find... Locate and select specified text Change... Replace specified text with new text You can select lines to be deleted, copied, moved, or edited by dragging, by triple clicking, and by shift-clicking. Or you can use the F4 "Mark" key. The Edit menu has eight commands that let you delete, copy, move and otherwise edit a block of lines The Edit Menu Cut Delete selected block Copy Copy selected block onto clipboard Paste Insert contents of clipboard into program Keep... Discard all but selected block Include... Insert specified file into program Edit... Restrict editing to selected block Select... Select specified block Select all Select entire program You may select the lines before you chhose the command, or you can choose the command first and then type line numbers to specify the block. To move part of your program from one place to another, first use Cut, move the insertion point, and then use Paste. Your True BASIC system disk includes four programs that will change the appearance of your current program. The Format Menu Do Num Add line numbers Du Unnum Remove line numbers Do Renum Resequence line numbers Do Format Emphasize keywords and indent structures Do... Choose a Do program Line numbers are completely optional in True BASIC. Pressing the > key when lines are selected moves the selection one space to the right; pressing the < key moves it to the left. Choose Print from the Project menu to list your current program on a printer. Choose Show Command from the Windows menu to activate the Command window. The F2 key will move your insertion point to the command window. If you`re already on the command line, pressing F2 will copy the last thing you typed onto the command line. press the F1 key to return to the source window. You can use the command window to debug your program. To breakpoint a line, select it and choose Breakpoint from the Run menu. When True BASIC executes that line, it will halt your program. Use the caommand window to debug the program, then use the Continue command to resume your program. The Most frequently used editing commands have the following keyboard shortcuts (Command=right Amiga key): Name Shortcut Change Command-E Copy Command-C Cut Command-X Find Command-F Paste Command-P Print Command-L The editing keys are: Key Meaning F1 Move to source window F2 Move to command window F3 Overtype F4 Mark line F5 Move to start of file F6 Move to end of file F7 Undo changes to line F8 Delete word to left F9 Delete word to right F10 Delete line to right ESC Delete line to left Backspace Delete character to left Del Delete character to right ADVANCED DECISION STRUCTURES The IF-TEHN-ELSE IF structure allows more flexibility in branching than the simple IF-THEN-ELSE structure. It lets you create multiple branches based on any logical conditions: IF condition1 THEN - - - - - - block1 - - - ELSE IF condition2 THEN - - - - - - block2 - - - ELSE IF condition3 THEN - - - - - - block3 - - - ELSE - - - - - - blockE - - - END IF The SELECT CASE structure provide another, often clearer, method of defining multiple branches. The form of the SELECT CASE structure is: SELECT CASE index CASE test1, test2, ... - - - - - - block of statements - - - CASE test3, test4, ... - - - - - - block of statements - - - CASE ELSE - - - - - - block of statements - - - END SELECT The tests in a CASE statement may have any of the following forms: constant IS operator constant constant TO constant The EXIT DO and EXIT FOR statements let you jump out from the middle of a loop, rather then executing all of the statements within the loop. Example Program ! Program to play a guessing game. ! RANDOMIZE LET answer = Int(Rnd*6) + 1 ! From 1 to 6 PRINT "I'm thinking of a number from 1 to 6." PRINT "You have 3 chances to guess it." PRINT FOR chance = 1 TO 3 PRINT "Enter your guess"; ! Ask for number INPUT guess ! Get a guess IF guess < 1 THEN ! Check it out PRINT "Must be at least 1." ELSE IF guess > 6 then PRINT "Can't be more than 6." ELSE IF guess < answer then PRINT "Too low." ELSE IF guess > answer then PRINT "Too high." ELSE ! Must be right PRINT "Correct!!!" STOP END IF END IF END IF END IF NEXT chance PRINT "The number was"; answer; "." END Example Program ! Craps game. ! RANDOMIZE FOR game = 1 to 10 ! Play 10 games LET die1 = Int(6*Rnd + 1) ! Roll 1 die LET die2 = Int(6*Rnd + 1) ! And the other LET dice = die1 + die2 ! Sum of two dice PRINT dice; ! Print this roll SELECT CASE dice ! Branch on roll CASE 2, 3, 12 ! dice = 2, 3, or 12 PRINT "You lose" CASE 7, 11 ! dice = 7 or 11 PRINT "You win" CASE ELSE ! Anything else LET point = dice ! Remember that roll DO LET die1 = Int(6*Rnd + 1) ! Roll again LET die2 = Int(6*Rnd + 1) ! Both dice LET dice = die1 + die2 PRINT dice; ! Print this roll LOOP until dice = 7 or dice = point IF dice=point then PRINT "You win" else PRINT "You lose" END SELECT NEXT game END MODULAR PROGRAMMING Subroutines and functions both provide methods of segmenting your True BASIC programs. A function returns a single numeric or string value to the calling program. A subroutine does not return one single value, but can change the values of parameters which are passed to it by the calling program. A function may be defined by a single line DEF statement, or by a block of lines beginning with a DEF statement and ending with an END DEF statement. A subroutine definition begins with a SUB statement and end with and END SUB statement. subroutines may have parameters, or values passed to them by the calling program. Parameters may be for the purpose of input to the subroutine, or they may be variables whose values are changed by the subroutine. Functions may also have one or more parameters. These parameters are for input only, since the value of the function itself is the only value returned to the calling program. Subroutines and functions may be internal or external. Internal subroutines and functions are part of the main program, and come before the END statement, while external ones are outside the main program and after the END statement. The primary difference is that internal subroutines and functions share variables with the rest of the program, while external ones do not. External subroutines and functions can be organised into libraries - collections of routines which can be used by any program. ARRAYS Every array must be named in a DIM statement before it`s used in the program. The DIM statement defines the number of dimensions for the array and the maximum number of elements in each dimension. Each item in an array is called an element. You refer to specifc elements by subscripts, which represent the element`s position in the array. Subscripts must be enclosed in parentheses. The subscripts of an array may have any numbers for their upper and lower bounds. For example: DIM a(5), b(-2 TO 2), c(6 TO 10) dimensions three arrays, each of which has five elements. Arrays may have as many as 255 dimensions on the Amiga. Example Program ! Inventory for 5 items. ! READ item1$, number1 READ item2$, number2 READ item3$, number3 READ item4$, number4 READ item5$, number5 PRINT "You have these items:" PRINT item1$, item2$, item3$, item4$, item5$ PRINT number1, number2, number3, number4, number5 DATA hammers, 4, umbrellas, 2, wood stoves, 1 DATA bags of salt, 4, pliers, 2 END Example Program ! Draw histogram of projected expenses. ! DIM expense(1980 to 1989) ! Bounds run from 1980 to 1989 FOR i = 1980 to 1989 ! Run through those years READ expense(i) ! Read projected expense IF expense(i) > max_exp then LET max_exp = expense(i) NEXT i SET window 1980, 1990, 0, 1.1*max_exp ! Set window FOR i = 1980 to 1989 ! Run through years BOX AREA i, i+.5, 0, expense(i) ! Draw bars NEXT i DATA 4000,4500,7000,8700,8900,11400,11200,10100,9800,9900 END Example Program ! State capital quiz. ! RANDOMIZE DIM state$(50,2) ! 50 states, 2 items per state FOR i = 1 to 50 READ state$(i,1) ! Read state name READ state$(i,2) ! And capital NEXT i FOR i = 1 TO 10 ! Ask 10 questions LET n = Int(50*Rnd) + 1 ! Pick a number between 1 and 50 PRINT "The capital of "; state$(n,1); " is"; LINE INPUT capital$ ! Get the reply IF Lcase$(capital$) = Lcase$(state$(n,2)) THEN ! Correct? PRINT "RIGHT!" ELSE PRINT "Nope, it's "; state$(n,2); "." END IF NEXT i DATA Alabama,Montgomery, Alaska, Juneau, Arizona,Phoenix DATA Arkansas,Little Rock, California,Sacramento DATA Colorado,Denver, Connecticut,Hartford, Delaware,Dover DATA Florida,Tallahassee, Georgia,Atlanta, Hawaii,Honolulu DATA Idaho,Boise, Illinois,Springfield, Indiana,Indianapolis DATA Iowa,Des Moines, Kansas,Topeka, Kentucky,Frankfort DATA Louisiana,Baton Rouge, Maine,Augusta, Maryland,Annapolis DATA Massachusetts,Boston, Michigan,Lansing DATA Minnesota,St. Paul, Mississippi,Jackson DATA Missouri,Jefferson City, Montana,Helena DATA Nebraska,Lincoln, Nevada,Carson City DATA New Hampshire,Concord, New Jersey,Trenton DATA New Mexico,Santa Fe, New York,Albany DATA North Carolina,Raleigh, North Dakota,Bismarck DATA Ohio,Columbus, Oklahoma,Oklahoma City, Oregon,Salem DATA Pennsylvania,Harrisburg, Rhode Island,Providence DATA South Carolina,Columbia, South Dakota,Pierre DATA Tennessee,Nashville, Texas,Austin, Utah,Salt Lake City DATA Vermont,Montpelier, Virginia,Richmond, Washington,Olympia DATA West Virginia,Charleston, Wisconsin,Madison DATA Wyoming,Cheyenne END THE MAT STATEMENTS The MAT statements provide the ability to work with entire arrays at once. Instead of creating a loop to work with each element of an array, you can use a single MAT statement. MAT READ corresponds to the simple READ statement, and reads values from DATA statements into one or more arrays: MAT READ array1, array2, ... The MAT PRINT statement prints the values of all the elements in an array. Commas and semicolons work hust as they do in the simple PRINT statements: MAT PRINT array1, array2, ... MAT PRINT array1; array 2; ... MAT INPUT and MAT LINE INPUT let you enter values for an entire array: MAT INPUT array1, array2, ... MAT LINE INPUT array1$, array2$, ... MAT INPUT array(?) The (?) subscript lets you input as many elements as you want. True BASIC will redimension the array to be just big enough to hold these elements. The MAT assigment statement lets you assign a single value to all variables in an array, or to assign one array to another: MAT array = constant MAT array1 = array2 True BASIC`s matrix arithmetic lets you add, subtract, and multiply arrays: MAT sum = a + b MAT diff = a - b MAT prod = a * b True BASIC follows the normal rules of matrix arithmetic. ADVANCED STRINGS True BASIC compares string values according to the ASCII code. This follows alphabetical order, except that all uppercase letters come before any lowercase letters. True BASIC concatenates strings with the ampersand (&) operator. True BASIC extracts substrings by giving the starting and endingpositions in the string: s$[start:end]. You can also change parts of an existing string by using a substring on the left side of a LET statement. True BASIC includes a number of built-in functions for operating with strings. Example Program ! Program to sort text in a list. ! DIM name$(1) ! We'll redim later CALL Get_list ! Get list of items LET n = Ubound(name$) ! How many we have CALL Sort_list ! Sort the list MAT PRINT name$ ! Now print sorted list SUB Get_list PRINT "Enter items to be sorted" MAT INPUT name$(?) ! Redimension to input END SUB SUB Sort_list FOR i = n to 2 step -1 FOR j = 1 to i-1 IF name$(j) > name$(j+1) then CALL Swap NEXT j NEXT i END SUB SUB Swap LET temp$ = name$(j) ! Temporary variable LET name$(j) = name$(j+1) LET name$(j+1) = temp$ END SUB END Example Program ! Haiku creator. ! RANDOMIZE DECLARE DEF Pick$ DIM article$(3), adjective$(15), noun$(12), verb$(15), prep$(4) MAT READ article$, adjective$ MAT READ noun$, verb$, prep$ LET line$ = Pick$(article$) & " " & Pick$(adjective$) LET line$ = line$ & ", " & Pick$(adjective$) & " " LET line$ = line$ & Pick$(noun$) & "--" PRINT line$ LET line$ = Pick$(prep$) & " " & Pick$(article$) & " " LET line$ = line$ & Pick$(adjective$) & " " & Pick$(noun$) PRINT line$ LET line$ = Pick$(article$) & " " & Pick$(noun$) & " " LET line$ = line$ & Pick$(verb$) & "." PRINT line$ DATA the, a, this DATA distant, foggy, wet, black, snowy, spring, sighing DATA broken, hidden, cold, ruined, stiff, forgotten DATA drowsy, gleaming DATA mountain, garden, shack, cloud, bamboo, stone DATA wheelbarrow, pine, field, sparrow, pathway, pond DATA rings, appears, disappears, remains, dissolves, shows DATA huddles, rises up, is still, creaks, sways, is hidden DATA seems lost, forgets itself, sleeps DATA under, by, within, beneath END ! ! Pick$. Choose an element of an array. ! DEF Pick$(array$()) LET n = Int(Rnd * Ubound(array$)) + 1 LET Pick$ = array$(n) END DEF Example Program ! Check for palindromes. ! DO PRINT "The phrase"; LINE INPUT phrase$ ! No error-checking IF phrase$ = "" THEN STOP ! Stop on null string LET reversed$ = "" ! Initialize reversed$ FOR i = Len(phrase$) to 1 step -1 ! Go thru backwards LET reversed$ = reversed$ & phrase$[i:i] ! Getting chars NEXT i PRINT "That's: "; reversed$ IF reversed$ = phrase$ THEN ! Check reversed & original PRINT "It's a palindrome." ELSE PRINT "Not a palindrome." END IF PRINT LOOP END PICTURES You can think of pictures in True BASIC as the graphic equivalent of subroutines: PICTURE Name (parameter1, parameter2, ...) - - - - - - PLOT ... - - - - - - END PICTURE Pictures are called in DRAW statements. You can combine various picture transformations to change the size of a picture, rotate it, or move the picture to a different location. The available transformations are: Name Meaning Shift(a, b) Move(x,y)to(x+a,y+b) Scale(a, b) Change(x,y)to(x*a,y*b) Scale(a) Change(x,y)to(x*a,y*a) Rotate(a) Rotate(x,y) a radians counterclockwise around origin Shear(a) Lean verical lines forward (i.e., to the right) a radians Pictures may be internal or external, and may be included in libraries. Example Program ! A picture of a triangle. ! PICTURE Triangle PLOT 0,0; 1,1; 1,0; 0,0 ! A triangle END PICTURE SET WINDOW 0, 16, 0, 10 ! Set the window DRAW Triangle ! Draw the triangle END Example Program ! Draws three houses using pictures ! SET WINDOW 0, 10, 0, 10 OPTION ANGLE degrees DRAW House with Scale(1) * Shift(7,6) DRAW House with Scale(1.5) * Shift(1.8,4) DRAW House with Rotate(45) * Scale(2,1.65) * Shift(6.2,1.8) END PICTURE House SET COLOR 3 PLOT AREA: -1,-1; -1,1; 1,1; 1,-1 ! The house itself SET COLOR 1 PLOT area: -1,1; 0,1.5; 1,1 ! Its roof PLOT area: -1,1; -1,1.4; -.8,1.4; -.8,1 ! and chimney SET COLOR 0 PLOT area: -.15,-1; -.15,-.3; .15,-.3; .15,-1 ! A door DRAW Window with Shift(-.5,-.5) ! and 4 windows DRAW Window with Shift(-.5,.5) DRAW Window with Shift(.5,.5) DRAW Window WITH Shift(.5,-.5) END PICTURE PICTURE Window SET COLOR 0 PLOT AREA: -.1,-.2; -.1,.2; .1,.2; .1,-.2 ! The window SET COLOR 1 PLOT -.1,0; .1,0 ! and its sills PLOT 0,-.2; 0,.2 END PICTURE AMIGA GRAPHICS Amiga Modes GRAPHICS Workbench screen, 640 X 200, 4 colours LOW2 320 X 200, 2 colours LOW4 320 X 200, 4 colours LOW 8 320 X 200, 8 colours LOW16 320 X 200, 16 colours LOW32 320 X 200, 32 colours LACELOW2 320 X 400, 2 colours, Interlaced LACELOW4 320 X 400, 4 colours, Interlaced LACELOW8 320 X 400, 8 colours, Interlaced LACELOW16 320 X 400, 16 colours, Interlaced LACELOW 32 320 X 400, 32 colours, Interlaced HIGH2 640 X 200, 2 colours HIGH4 640 X 200, 4 colours HIGH8 640 X 200, 8 colours HIGH16 640 X 200, 16 colours LACEHIGH2 640 X 400, 2 colours, Interlaced LACEHIGH4 640 X 400, 4 colours, Interlaced LACEHIGH8 640 X 400, 8 colours, Interlaced LACEHIGH16 640 X 400, 16 colours, Interlaced To switch to a new mode use the SET MODE command. For instance: set mode "high16" switches to HIGH16 mode. If you use a name that True BASIC doesn`t recognise, it uses mode GRAPHICS instead. (That is, it uses the full Workbench screen for output.) The Amiga clears the screen when you switch modes. The SET and ASK statements, for colours, reflect the current graphic mode. ASK MAX COLOR returns the numbers of foreground colours for the current mode. SET COLOR changes to a new foreground colour. ASK COLOR returns the current foreground colour. ASK COLOR MIX returns the actual color levels used by the Amiga. LIBRARIES Your True BASIC syetem disk includes several library files of functions and subroutines that supplement the True BASIC language. Four of the libraries contain mathematical functions; one contains subroutines for drawing graphs; and one contains subroutines for using menus. Your disk also contains a library, AmigaLib*, that lets you get at some of the Amiga`s special features. This library is written in True BASIC, C, and assembly language. These libraries are all in a directory named "Libs". You will need to add the directory name to your LIBRARY statement when you use these libraries - for example: library "Libs/AmigaLib*" MATHEMATICAL FUNCTIONS The four math libraries are: FnhLib Hyberbolic functions FntLib Trigonometric functions (in radians) FntdLib Trigonometric functions (in degrees) FnmLib Math functions Their file names and functions are listed below: Library File FnhLib Include file Functions Explanation Fnh Sinh(a) Hyperbolic sine of a Cosh(a) Hyperbolic cosine of a Tanh(a) Hyperbolic tangent of a Coth(a) Hyperbolic cotengent of a Sech(a) Hyberbolic secant of a Csch(a) Hyperbolic cosecant of a Asinh(a) Hyperbolic arcsine of a Acosh(a) Hyperbolic arccosine of a Atanh(a) Hyperbolic arctangent of a Acoth(a) Hyperbolic arccotangent of a Asech(a) Hyperbolic arcsecant of a Acsch(a) Hyperbolic arccosecant of a Library file FntLib Fnt Cot(a) Cotangent of a Sec(a) Secant of a Csc(a) Cosecant of a Asin(a) Arcsine of a Acos(a) Arccosine of a Acot(a) Arcotangent of a Asec(a) Arcsecant of a Acsc(a) Arccosecant of a Library file FntdLib Fntd Cot(a) Cotangent of a Sec(a) Secant of a Csc(a) Cosecant of a Asin(a) Arcsine of a Acos(a) Arccosine of a Acot(a) Arccotangent of a Asec(a) Arcsecant of a Acsc(a) Arccosecant of a Libary file FnmLib Fnm Logbase(x,b) Log of x to the base b Erf(x) Error function: Erf(x)= 2*Norm1(Sqr(2)*x) Normal(a,b) Area under the normal curve from a to b Norm1(x) Area under the normal curve from 0 to x Factrl(n) n factorial Binom(n,j) Binomial coefficient Binompr(n,j,p) Binomial distribution Poisson (m,j) Poisson distribution The "Include file" listed for each library file contains a LIBRARY statement with the appropriate file name, and DECLARE DEF statement(s) that declare the appropriate functions. File Fntd also contains an OPTION ANGLE DEGREES statement, so that functions in library file FntdLib expect all angles to be measured in degrees. To use one of the above libraries in you program, therefore, all you have to do is include the corresponding file. Move your insertion point to the first line in your program. Choose include from the Edit menu, select the name of the include file that corresponds to the library you want to use, and click the include button. For example to use Library FnhLib, include Fnh. The following statements will be added to your file: library "Libs/FnhLib" declare def Sinh, Cosh, Tanh, Coth, Sech, Csch declare def Asinh, Acosh, Atanh, Acoth, Asech, Acsch You can then use any of the twelve hyperbolic functions in your programs just as if they were part of the True BASIC language. GRAPHICS SUBROUTINES The GraphLib library contains several graphic subroutines. The following list gives the form of the CALL statement and an explanation of each subroutine. CALL Arc(x,y,r,a1,a2) Draws and arc of the circle with centre at (x,y) and radius r. The arc is from a1 to a2, where a1 and a2 are angles in degress. CALL Axes Draws the X- and Y-axes of your current window. CALL Bars(data,n) Draws a bar graph of n numbers stored in the one-dimensional array data. Bars sets its own window. CALL Fplot(a,b) Draws a line graph of function F from a to b. You must define function F(x) as an external function. Fplot sets its own window. CALL Frame Draws a frame around your current window. CALL Polygon(x1,x2,y1,y2,n) Draws an n-sided polygon within a box defined by coordinates x1,x2,y1, and y2. CALL Ticks(a,b) Draws the X- and Y-axes of your current window, with tick marks a units apart on the X-axes and b units apart on the Y-axes. To use any of these subroutines in your program, just add the statement: library "Libs/GraphLib" at the beginning of your program. MENU SUBROUTINES Library MenuLib contains five subroutines for using "push button" menus. These menus, unlike the usual "pull down" menus, have all items visible on the screen at the same time. The items look like OK and Cancel buttons. MenuLib lets you choose the placement of the menu on your screen, the number of items in the menu, and the button labels. Menu items must be selected by clicking one of the buttons; the subroutines check that the responses are legal. The menus are displayed in a seperate window, #9. Prompts and choices are diplayed in whatever window your program has opened (the "working window"). The five menu subroutines are: Menu_set Opens the menu window, #9, and sets the parameters for the other menu subroutines. Menu_all Displays the menu and prompt, gets a choice and diplays it, clears the menu window, and returns to the working window. Menu Displays the menu and gets a choice. Menu_show Displays the menu. Menu_ask Gets a choice. Their parameters are explained in detail below. To use any of thesubroutines, add the statement: libary "Libs/MenuLib" to your program, before any statements that CALL the subroutines. You should first call the subroutine Menu_set, which opens the menu window, #9, and sets the parameters of menu placement, number of items, and size of items for the other routines. After calling Menu_set, you can use any of the other four to display the menu and process the choice, but Menu_all is the most general. Most applications can be handled by using only Menu_set and Menu_all. Menu_set requires a CALL statement of the form: CALL Menu_set(where$, c$, maxent, maxlen, menu$, $9) The parameters have the following meanings: where$ Placement of menu. where$ may be "top", "bottom", "left", or "right", in upper of lowercase letters. c$ Colour for the menu window. maxent Maximeum number of entries in any menu. maxent cannot be greater than ten. maxlen Maximum length of a menu item, maxlen cannot be greater then ten. menu$ menu$ is a packed variable that is used by all the other menu subroutines. You should not try to chanhe menu$. #9 Window #9 is where the menu will be displayed. The CALL statement for subroutine Menu_all has the form: CALL Menu_all (M$, m, prompt$, ans, menu$, #n, #9) The parameters are: M$ A one dimensional string array containing the menu items. m The number of menu items in thelist M$. m cannot be greater than the value of maxent given in the call to Menu_set. prompt$ The prompt that will be displayed in the working window. ans The menu item chosen (a number from 1 to m) menu$ the packed string created by Menu_set. You should not try to use menu$. #n The working window opened in your program. n must be a numeric constant between 1 and 1000. #9 The menu window opened by Menu_set. The Amiga Library Your disk also contains AmigaLib*, a special library of Amiga subroutines. This library is written in a mixture of True BASIC, C, and assembly language. We`ve combined the results into a single, compiled library, but your disk also contains the seperate source files. CALL Say(speech$) Speaks the given speech$ aloud, using the Amiga`s voice synthesizer CALL Cycle(color$,inc) Cycles the colour mixes for the active colours on the screen. The string color$ contains a strangely packed string representing the colours to use. The Rainbow$ function, below, gives a rainbow colour cycle. The expression inc gives the "step" to use when cycling through the colours: +1 cycles one way, -1 cycles the other, and so forth. LET color$=Rainbow$ Rainbow$ gives a color$ string suitable for use with the cycle subroutine. It contains the colours of the rainbow. Rainbow$ is a True BASIC function: see its source code for a description of the format of color$ string. CALL CLI(command$) CLI issues a CLI command command$. Output produced by this command is normally discarded. To see the output and to execute commands interactively, give the null string as a command. This will open a new, independant CLI window. This subroutine causes an exception if the CLI can`t be used - for instance, if the Amiga is running low on memory or if the command program RUN isn`t present in the C: logical device. LET filename$=GetFile$(x,y,type$,button$) GetFile$ presents an Open box on the screen, lets the user select a file name, and returns that file name. As usual, the user can switch disks and directories while using the Open box. If the user clicks Cancel, GetFile$ returns a null string. The x and y coordinates give the pixel location of the top left corner of the box. The Type$ is included only for compatability with GetFile$ on other brands of computers, it`s ignored on the Amiga. The button$ text replaces "Open" in the Box`s button. It can be up to 7 characters long. To use any of these routines, add a library statement to the start of your program; add the DECLARE DEF statement only if you want to use Rainbow$ or GetFile$ funtions: library "Libs/AmigaLib*" declare def Rainbow$, GetFile$ The program spirograph shows how to use the Cycle and Rainbow$ routines. The program Speackup shows how to use the Say subroutine. Both programs are in the Demos directory. TRUE BASIC AMIGA COMMAND LIST Syntax for commands: block may ba a line number, range of lines, routine name, orselected line(s). filename may be any valid filename. text may be any word or number in your program, or any characters enclosed in "quotes". Commands Type on Command line in Command window. BREAK BREAK block CHANGE old,new where old and new are text COMPILE CONTINUE COPY from,to where from and to are blocks DELETE block DO filename DO FORMAT DO NUM DO RENUM DO UNNUM EDIT EDIT block FILES INCLUDE filename KEEP block KEY KEY FROM filename KEY TO filename LIST LIST block LOCATE text MARK MARK block MOVE block1,block2 NEW OLD filename REPLACE filename RUN SAVE filename TO block TRY old,new where old and new are text UNSAVE filename Mathematical functions Abs(x) Divide(x,y,q,r) Eps(x) Exp(x) Int(x) Log(x) Log2(x) Log10(x) Max(x,y) Maxnum Min(x,y) Mod(x,y) Remainder(x,y) Rnd Round(x) Round(x,n) Sgn(x) Sqr(x) Truncate(x,n) Trigonometric functions Angle(x,y) Atn(x) Cos(x) Deg(x) Pi Rad(x) Sin(x) Tan(x) String functions Chr$(n) Len(a$) Lcase$(a$) Ltrim$(a$) Ord(a$) Pos(a$,b$) Repeat$(a$,n) Rtrim$(a$) Str$(n) Trim$(a$) Ucase$(a$) Using$(fmt$,a) Val(a$) Date and time functions Date Time Date$ Time$ Ask statements BACK var #n: ACCESS var$ COLOR var #n: FILESIZE var COLOR MIX (color) r,g,b CURSOR var$ #n: MARGIN var CURSOR line,column #n: NAME var$ FREE MEMORY var #n: ORIGANIZATION var$ MARGIN var #n: POINTER var$ MAX COLOR var #n: RECORD var MAX CURSOR line,column #n: RECSIZE var MODE var$ #n: ZONEWIDTH var SCREEN x1,x2,y1,y2 WINDOW x1,x2,y1,y2 ZONEWIDTH var BOX AREA left,right,bottom,top BOX CIRCLE left,right,bottom,top BOX CLEAR left,right,bottom,top BOX ELLIPSE left,right,bottom,top BOX KEEP left,right,bottom top IN var$ BOX LINES left,right,bottom,top BOX SHOW var$ AT left,bottom BOX SHOW var$ AT left,bottom USING expr CALL subr (expr1,expr2,...) CAUSE ERROR expr CAUSE ERROR expr,expr$ CHAIN expr$ CHAIN expr$,RETURN CHAIN expr$ WITH (arg$) CHAIN expr$ WITH (arg$), RETURN CLEAR CLOSE #expr DATA item1,item2,... DECLARE DEF func1,func2,... DEF func(var1,var2,...) = exp DEF func(var1,var2,...) ... LET func=expr ... END DEF DIM array(bound,bound,...),... DIM array(low TO high,low TO high,...),... DO WHILE condition ... WHILE condition ... UNTIL condition LOOP DRAW picture DRAW picture WITH transform*transform* ... END ERASE #expr EXIT DEF EXIT DO EXIT FOR EXIT HANDLER EXIT SUB EXTERNAL FLOOD x,y FOR var = first TO last STEP size ... ... NEXT var GET KEY var GET MOUSE x,y,state GET POINT x,y GOSUB line-number GOTO line-number IF condition THEN statement IF condition THEN statement1 ELSE statement2 IF condition THEN ... ... END IF IF condition THEN ... ... ELSE IF condition THEN ... ... ELSE ... ... END IF INPUT var1,var2,... INPUT PROMPT expr$,var1,var2,... LINE INPUT var1$,var2$,... LINE INPUT PROMPT expr$,var1$,var2$,... INPUT statements can be used with files. Add a channel number, such as: INPUT #expr:a$ LINE INPUT #expr,PROMPT expr$,var1$,var2$,... LET var1,var2,...=expr LET var1$(start:end)=expr$ LIBRARY "filename","filename",... MAT array=(expr) MAT array=array1+array2 MAT array=array1-array2 MAT array=arrat1*array2 MAT array-Inv(array1) MAT array=Trn(array1) MAT PLOT AREA: array MAT PLOT LINES: array MAT PLOT POINTS: array MAT may also precede any INPUT,PRINT,READ, or WRITE statement. If so, the statement reads/writes arrays rather then ordinary variables. ON expr GOSUB line-number,line-number,... ON expr GOSUB line-number,line-number,...ELSE line-number ON expr GOTO line-number,line-number,... ON expr GOTO line-number,line-number,...ELSE line-number OPEN #expr:NAME expr$, ACCESS accmode$ , CREATE crtmode$ , ORGANIZATION orgmode$ , RECSIZE recsize accmode$ can be "INPUT", "OUTPUT", "OUTIN" crtmode$ can be "NEW", "OLD", "NEWOLD" ormode$ can be "TEXT", "RECORD", "BYTE" OPEN #expr:PRINTER OPEN #expr:SCREEN left,right,bottom,top OPTION ANGLE DEGREES OPTION ANGLE RADIANS OPTION BASE constant PAUSE expr PICTURE Pic(var1,var2,...) ... ... END PICTURE PLAY music$ PLOT x1,y1;x2,y2;... PLOT AREA:x1,y1;x2,y2;... PLOT LINES:x1,y1;x2,y2;... PLOT POINTS:x1,y1;x2,y2;... PLOT TEXT,AT x1,y1:expr$ PRINT expr1,expr2,... PRINT expr1;expr2;... PRINT USING format$:expr1,expr2,... PROGRAM name PROGRAM name(var$) RANDOMIZE READ var1,var2,... READ #expr:var1,var2,... READ #expr,BYTES expr:var1,var2,... REM RESET RESTORE RETURN SELECT CASE expr test may be CASE test1,test2,... ... constant ... low TO high CASE test3,test4,... IS op constant ... ... op can be <,=,<>, etc CASE ELSE ... ... END SELECT Set Statements BACK expr #n:MARGIN expr COLOR expr #n:POINTER BEGIN COLOR MIX (color) r,g,b CURSOR expr$ #n:POINTER END CURSOR line,column #n:POINTER NEXT MARGIN expr #n:POINTER SAME MODE name$ #n:RECORD expr WINDOW x1,x2,y1,y2 #n:RECSIZE expr ZONEWIDTH expr #n:ZONEWIDTH expr SOUND freq,time STOP SUB subr(var1,var2,...) ... ... END SUB UNSAVE expr$ WHEN ERROR IN ... ... USE ... ... END WHEN WINDOW #expr WRITE #expr:expr1,expr2,... Formatting characters for PRINT USING statement and Using$ function + print number with leading "+" or "-" - print number with leading space or "-" $ print number with leading dollar sign * print leading zeros as "*" % print leading zeros as "0" # print leading zeros as spaces , insert comma here if appropriate . align decimal point here ^ exponent field < left justify string > right justift string ERROR MESSAGES Argument types don`t match. Your`e calling a routine with some argumanets, but earlier in your program you defined or called the same routine with different arguments. Either you`re giving a different number of arguments in the calls, or their types are different - you`re passing strings instead of numbers, or vice versa. Check this call against preceding calls, and against the routine`s definition. Bad FIND item; try using quotes. When you`re trying to find a string which contains a comma or double quote marks, you must enclose the entire string with double quote marks. (These rules are the same as for strings in INPUT replies or DATA statements.) Badly formed USING string. (8201) The format string in your Using$ function or PRINT USING statement is incorrect. One of the format items doesn`t follow True BASIC`s rules. Badly formed input line. (8105) The reply to an INPUT statement (either from a file or from the keyboard) is badly formed. Most lekely you have not properly matched up opening and closing quote marks. Can`t change that key. True BASIC does not let you change the meanings of any of the normal, printing characters. Can`t continue. You`ve just given a CONTINUE command, to resume running a suspended program. However, True BASIC cannot continue the program. There are several possible reasons. You cannot continue a program that you haven`t yet started running, or one which you`ve just changed. You cannot continue a program which stopped because an error occured. And you cannot continue a suspended program afeter using a DO command. If you are trying to debug a program which stopped because of an error, try using the BREAK command to insert breakpoints before the erroneous line, and then run the program again. Can`t copy region itself. The True BASIC editor does not let you copy a region into itself. For instance, you may not make a copy of some subroutine within that subroutine. If you really want to, you can put a copy of the region somewhere else, and then move this copy into the original region. Can`t do graphics on this computer. (11000) Your computer cannot draw graphics. (Not for Amiga) Can`t edit compiled program, Your program is compiled, and so cannot be changed. Can`t erase file not opened as OUTIN. (7301) You may not use the ERASE statement on a file, unless the file has been opePLAY music$ PLOT x1,y1;x2,y2;... PLOT AREA:x1,y1;x2,y2;... PLOT LINES:x1,y1;x2,y2;... PLOT POINTS:x1,y1;x2,y2;... PLOT TEXT,AT x1,y1:expr$ PRINT expr1,expr2,... PRINT expr1;expr2;... PRINT USING format$:expr1,expr2,... PROGRAM name PROGRAM name(var$) RANDOMIZE READ var1,var2,... READ #expr:var1,var2,... READ #expr,BYTES expr:var1,var2,... REM RESET RESTORE RETURN SELECT CASE expr test may be CASE test1,test2,... ... constant ... low TO high CASE test3,test4,... IS op constant ... ... op can be <,=,<>, etc CASE ELSE ... ... END SELECT Set Statements BACK expr #n:MARGIN expr COLOR expr #n:POINTER BEGIN COLOR MIX (color) r,g,b CURSOR expr$ #n:POINTER END CURSOR line,column #n:POINTER NEXT MARGIN expr #n:POINTER SAME MODE name$ #n:RECORD expr WINDOW x1,x2,y1,y2 #n:RECSIZE expr ZONEWIDTH expr #n:ZONEWIDTH expr SOUND freq,time STOP SUB subr(var1,var2,...) ... ... END SUB UNSAVE expr$ WHEN ERROR IN ... ... USE ... ... END WHEN WINDOW #expr WRITE #expr:expr1,expr2,... Formatting characters for PRINT USING statement and Using$ function + print number with leading "+" or "-" - print number with leading space or "-" $ print number with leading dollar sign * print leading zeros as "*" % print leading zeros as "0" # print leading zeros as spaces , insert comma here if appropriate . align decimal point here ^ exponent field < left justify string > right justift string ERROR MESSAGES Argument types don`t match. Your`e calling a routine with some argumanets, but earlier in your program you defined or called the same routine with different arguments. Either you`re giving a different number of arguments in the calls, or their types are different - you`re passing strings instead of numbers, or vice versa. Check this call against preceding calls, and against the routine`s definition. Bad FIND item; try using quotes. When you`re trying to find a string which contains a comma or double quote marks, you must enclose the entire string with double quote marks. (These rules are the same as for strings in INPUT replies or DATA statements.) Badly formed USING string. (8201) The format string in your Using$ function or PRINT USING statement is incorrect. One of the format items doesn`t follow True BASIC`s rules. Badly formed input line. (8105) The reply to an INPUT statement (either from a file or from the keyboard) is badly formed. Most lekely you have not properly matched up opening and closing quote marks. Can`t change that key. True BASIC does not let you change the meanings of any of the normal, printing characters. Can`t continue. You`ve just given a CONTINUE command, to resume running a suspended program. However, True BASIC cannot continue the program. There are several possible reasons. You cannot continue a program that you haven`t yet started running, or one which you`ve just changed. You cannot continue a program which stopped because an error occured. And you cannot continue a suspended program afeter using a DO command. If you are trying to debug a program which stopped because of an error, try using the BREAK command to insert breakpoints before the erroneous line, and then run the program again. Can`t copy region itself. The True BASIC editor does not let you copy a region into itself. For instance, you may not make uare matrix, since the determinant is mathematically defined only for such matrices. Disk full. (9006) You are writing output to a file, and the disk has become full. Diskette removed, or wrong diskette. (9005) You had opened a file, but while True BASIC was using it, you removed the disk and inserted another one. Don`t switch diskswhile they`re in use! Division by zero. (3001) One of your expressions tried to divide some quantity by zero. If you want to substitute the largest possible number and continue (without an error), enclose the expression in a WHEN statement: when error in let x=(1+2+3)/0 use let x=Maxnum end when Maxnum is a True BASIC function which gives the largest possible number available on your computer. Doesn`t belong here. The cursor points to some word in your program which doesn`t make sense. Ending doesn`t match beginning. You are using a structured statement, such as a FOR-NEXT or IF- THEN-ELSE, and the ending statement doesn`t properly match the beginning of the structure. Most likely you have forgotten the ending statement for some structure within this one. Or you may have begun a FOR loop using one index variable, but used another variable on the NEXT statement. Error in PLAY string. (4501) The string given in your PLAY statement doesn`t follow True BASIC rules. Expected "thing" The cursor points to a spot where True BASIC expected some word or punctuation, but found something else. Expected relational operator. The cursor points to a spot where you must put a relational operator, such as "=" or "<". (Note that True BASIC does not allow statements like "IF a THEN ...", as do some other BASICs. Change such statements to "IF a<>0 THEN...".) File already exists. (9004) You are trying to create a new file, but it already exists. Check to make sure you have given the correct filename. If you want to overwrite an existing file, change the CREATE NEW in the open statement to CREATE NEWOLD. Or use the REPLACE command instead of SAVE. File is read or write protected. (9001) You are trying to read or write a file but your operating system has write or read-protected this file. File pointer out of bounds. (7252) You are trying to use the RESET or SET POINTER or SET RECORD statement to change a file`s pointer. However the position you`vegiven is either less than 1, or past the end of the file. File`es record size doesn`t match open OPEN RECSIZE. (7103) Each record file has its RECSIZE built into it. The RECSIZE of the file you`re trying to open doesn`t match the RECSIZE given in your OPEN statement. IDN must make a square matrix. (6004) Identity matrices must be square. Therefore when you use the Idn(x,y) function, you must make sure that x=y. Illegal array bounds for name in routine You`ve defined an array where the upper bound is less than the lower bound. Illegal channel. You`ve written a SET or ASK statement that requires a channel number, but doesn`t have one. Or you`ve added a channel number to a SET or ASK statement that doesn`t allow one. Illegal data. Your DATA statement is not properly written. Illegal exit. You`ve written an EXIT DO statement outside of any DO-LOOPS, or an EXIT-FOR outside of any FOR loop, etc. Or you have written unknown kind of EXIT statement. Illegal expression. The cursor points somewhere within an expression that doesn`t follow True BASIC`s rules. Illegal keyword. The cursor points to a word that doesn`t make sense in that location. Illegal number. The cursor points to a spot where a number is required, but you`ve given something else. Illegal option. Make sure you`ve spellled ANGLE,BASE,DEGREES,and RADIANS properly. Illegal parameter. You`ve written a SUB, DEF, or PICTURE statement, defining a routine. Something is wrong with one of the paramaters in the parameter list. Illegal statement. Each statement must beging with a True BASIC keyword, such as LET or SELECT. Improper NUM string. (4020) The string you`ve given to the NUM fuction doesn`t represent an IEEE 8-byte floating point number. Improper ORD string. (4003) The Ord function requires either a one-character string, or a string giving the official name of an ASCII character. No leading or trailing spaces are allowed. Input item bigger then RECSIZE. (8302) This message is only given for damaged record files. INV needs a square matrix. (6003) Matrix inversion is defined only for square matrices. LBOUND out of range. (4008) You are using a call such as Lbound(A,3) and the array A doesn`t have three dimensions. LOG of number <=0. (3004) Logarithms are only defined for positive numbers. MARGIN less than zonewidth. (4006) Your SET MARGIN statement is trying to set a margin less then the zonewidth. Mismatched array sizes. (6001) You`re using a MAT statement which requires arrays of the same size, but the arrays are different sizes. Missing end statement. All True BASIC programs must contain END statements. MOD and REMAINDER can`t have 0 as 2nd argument. (3006) The Mod and Remainder functions do not allow zero as their second argument, since this is equivalent to dividing by zero. Must be a function name. You`ve written a DEF or FUNCTION statement, but no proper function name follows the DEF or FUNCTION. Must be a number. Use a number, not an expression. Must be a picture name. Your DRAW statement names something other than a picture. Must be a string constant. Use a constant, not an expression. Must be a subroutine name. The CALL statement can only be used to call subroutines. Must be a variable. You`ve used an expression, or a routine name, in a place whereonly a variable is permitted. Must be an array. You must give an array variable. Must be a byte file for READ BYTES. (7351) You`re tring to use a READ BYTES statement on a text or record file. Must be byte file or empty for SET RECSIZE. (7251) SET RECSIZE can only be used or byte files, or on empty record files. Must be record or byte file for SET RECORD. (7202) SET RECORD cannot be used on text files. You may reset a text file`s pointer only to the very beginning or very end of the file. Must be record or byte file. (8502) You`re using the READ or WRITE statement on a text file, or on a window. Must be a text file. (8501) You`re using an INPUT or PRINT statement on a record file or a byte file. Must SET RECSIZE before WRITE. (8304) You cannot write to an empty record file without somehow first indicating the file`s record size. You may either execute a SET RECSIZE statement before the first WRITE statement, or you may specify the file`s record size in the OPEN statement. Name can`t be redefined. You can`t use the same name for two different things. Negative number to non-intergral power. (3002) You`re trying to compute n^x but n is negative and x is not an integer. No CASE selected, but no CASE ELSE. (10004) You have executed a SELECT CASE statement, but no CASE test has succeeded. Since you didn`t have a CASE ELSE block to catch this problem, True BASIC prints this error message. No GET MOUSE on this computer. (8700) You computer does not support a mouse. (Not Amiga). No main program. Your current file contains only functions, pictures, and/or subroutines - but no main program. No saved copy - still want to compile? Compile requester. No such color. (11008) You`re using the SET COLOR statement with some colour name that True BASIC doesn`t recognize. No such file. (9003) You`re trying to use a file which doesn`t exist. No such function or subroutine. You`ve named a function, subroutine, or picture in a command, but this routine doesn`t exist. No such line numbers. You`ve given a range of line numbers in a command, but no lines have those numbers. No USING item for ouput. (8202) The format string in your Using$ function or PRINT USING statement has no formatting items in it. Not found. You`ve used the FIND key to find some word or phrase, but it wasn`t found. ON index out of range, no ELSE given. (10001) You`ve used an ON GOTO or ON GOSUB statement, and the number on which you`re branching is out of range. Out of memory. (5000) Out of memory - get more add-on memory! Ouput item bigger than RECSIZE. (8301) You`re trying to write an item to a record file, but it doesn`t fir within the record size established for that file. Overflow. (1000) You`ve computed a number bigger than the one your computer can handle. Please say what lines you mean. Mark the lines. Please try "CHANGE old,new". Give both old and new phrases. Please try "DO filename". You must give a file name when using the DO command. Please try "INCLUDE filename". You must give a file name when using the INCLUDE command. Please try "KEY" or "KEY FROM file" or "KEY TO file". You must give a file name. Please try "LOCATE item". You must give the phrase to be located. Please try "OLD filename". You must give a file name. Please try "SAVE filename" or "REPLACE filename". You must give a filename. Please try "UNSAVE filename@. You must give a filename. Please type line numbers as 100 or 100-150. True BASIC can`t understand a command such as DELETE with the line numbers you have given. Program stopped. You pressed the STOP key. REPEAT$ count <0. (4010) You`re using the Repeat$(a$,n) function, but n is less than zero. Reading past end of data. (8001) You`ve executed a READ statement, but have run out of DATA items to read. Reading past end of file. (8011) You`re trying to read more than exists in the file. RETURN without GOSUB. (10002) You`ve just executed a RETURN statement, but there has been no corresponding GOSUB instruction. Screen bounds must be 0 to 1. (11003) The bounds given on an OPEN SCREEN statement must lie in the range from 0 to 1, inclusive. No matter how big your screen is, the left and bottom edges are defined to be 0; the rifht and top edges are defined to be 1. Screen minimum >+ maximum. (11002) Incorrect OPEN SCREEN values. SIZE index out of range. (4004) You`re trying to take SIZE(A,3) for instance, when the array A has fewer than 3 dimensions. SQR of negative number. (3005) You are trying to take the square root of a negative number. Statement outside of program. Statement is outside your main program, but is not included within any external routine. String given instead of number. (8103) You`ve executed an INPUT statement which is trying to input a number. However the reply given isn`t a number. String too long. (1051) You`ve tried to create a string longer than 1,048,575 characters. Subscript out of bounds. (2001) You`ve given an array subscript that lies outside the array`s bounds. TAB column not between 1 and margin. (4005) You`ve used the TAB function in a PRINT statement, but its argument doesn`t lie between 1 and the current margin. The BYE command is just "BYE". When you want to leave True BASIC just type BYE. This must first appear in a DIM or DECLARE DEF. True BASIC doesn`t know if it`s an array or a function. Too few input items. (8002) You`ve executed an INPUT statement, and the input reply doesn`t contain as may items as requested. Too many channels open. (7102) You have tried to open more than 10 channels. Too many input items. (8003) You`ve executed an input statement and the input reply line contains more items than requested. Trouble using disk or printer. (9002) Printer or disk problem. Type is wrong for name in routine You`ve tried calling a routine named routine within another routine named routine. However you got the arguments wrong in this call - they don`t match the parameter list. UBOUND out of range. (4009) You`ve tried calling something like Ubound(a,3), where a is an array with less than 3 dimensions. Undefined routine name in routine The routine named routine has tried to use a function, subroutine, or picture called name. But this is nowhere defined. Unknown OPEN option. (7101) Option doen`t exist. VAL string isn`t a proper number. (4001) You`ve called the Val function, but the string you gave doesn`t properly represent a number. What? (Please type HELP.) Unknown command. Window minimum=maximum (11001) You`ve executed a SET WINDOW statement which sets the vertical or horizontal window maximum equal to the minimum. Wrong number of arguments. You`re calling a function, subroutine, or picture, but specifying the wrong number of arguments. Wrong number of dimensions. You`re trying to use an array, but have given the wrong number of dimensions. Wrong type. You`re tring to use a string where a number is needed, or a number where a string is needed. Wrong type of file. (7104) Wrong type of file for OPEN statement. You have two routines called name in routine. In the routine named routine, you`ve defined two different routines called name. Zero to negative power. (3003) You`re trying to compute 0^n, where n<0. ZONEWIDTH out of range. (4007) You`ve executed a SET ZONEWIDTH statement, trying to set the zonewidth less than 1, or greater than the margin. - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - Printed by COL 1 March 1988 HAVE FUN!!!