Character Set¶

BASIC-80 uses the ASCII character set.

Valid Characters¶

BASIC-80 programs can use:

Letters: A-Z (uppercase and lowercase) Digits: 0-9 Special symbols: See below

Special Characters in BASIC¶

Character	Name	Usage
"	Quote	String delimiters: `"Hello"`
'	Apostrophe	Comment: `10 ' Comment`
:	Colon	Statement separator: `A=5:B=10`
;	Semicolon	Print separator, statement continuation
,	Comma	List separator, print tab
.	Period	Decimal point: `3.14`
+	Plus	Addition, positive sign
-	Minus	Subtraction, negative sign
*	Asterisk	Multiplication
/	Slash	Division
\	Backslash	Integer division
^	Caret	Exponentiation: `2^3`
=	Equals	Assignment, comparison
<	Less than	Comparison
>	Greater than	Comparison
(	Left paren	Grouping, function calls
)	Right paren	Grouping, function calls
$	Dollar	String type suffix: `NAME$`
%	Percent	Integer type suffix: `COUNT%`
!	Exclamation	Single precision suffix: `X!`
#	Hash	Double precision suffix: `PI#`, file number
&	Ampersand	Hexadecimal/octal prefix: `&HFF`, `&O77`
_	Underscore	Allowed in variable names (some versions)

String Characters¶

Strings can contain any printable ASCII characters (32-126):

10 A$ = "Hello, World!"
20 B$ = "123 Main St."
30 C$ = "!@#$%^&*()"

Control Characters¶

BASIC supports some control characters:

Code	Character	Usage
7	BEL	Bell/beep: `PRINT CHR$(7)`
8	BS	Backspace
9	TAB	Tab character
10	LF	Line feed (new line)
13	CR	Carriage return (return to line start)
27	ESC	Escape character

Use CHR$() to include control characters in strings.

Reserved Words¶

Cannot be used as variable names:

All BASIC statements (PRINT, FOR, IF, etc.)
All functions (SIN, COS, LEFT$, etc.)
Reserved keywords (AND, OR, NOT, TO, STEP, etc.)

See: Statements, Functions

Variable Names¶

Valid variable names: - Start with a letter (A-Z) - Can contain letters and digits - Can end with type suffix ($, %, !, #) - Maximum length varies by implementation

Valid:

A
X1
NAME$
COUNT%
TOTAL
VALUE123

Invalid:

2X          ' Cannot start with digit
A+B         ' Cannot contain operators
FOR         ' Reserved word
PRINT$      ' Reserved word

Case Sensitivity¶

BASIC-80 is not case sensitive:

10 Print "Hello"     ' Same as PRINT
20 FoR I = 1 To 10   ' Same as FOR and TO

Convention: Use UPPERCASE for keywords, mixed case for variables.

Line Terminators¶

Programs can use different line endings: - CR+LF (Windows: \r\n) - LF (Unix/Linux: \n) - CR (Old Mac: \r)

MBASIC accepts all formats.

Comments¶

Two ways to add comments:

10 REM This is a comment
20 ' This is also a comment

Everything after REM or ' is ignored.

String Escaping¶

BASIC does not have escape sequences like \n or \t.

Use CHR$() instead:

10 PRINT "Line 1" + CHR$(10) + "Line 2"    ' Newline
20 PRINT "Col1" + CHR$(9) + "Col2"         ' Tab

Hexadecimal and Octal¶

Use &H for hexadecimal, &O for octal:

10 HEX = &HFF      ' 255 in hex
20 OCT = &O77      ' 63 in octal
30 PRINT HEX, OCT

Whitespace¶

Spaces - Usually ignored, but required between keywords
Tabs - Treated as spaces
Blank lines - Allowed in programs

10PRINT"OK"           ' Works but hard to read
10 PRINT "Better"     ' Recommended

Special Sequences¶

Line continuation: Not supported in MBASIC 5.21. Use : to combine statements:

10 A = 1 : B = 2 : C = 3

String concatenation:

10 FULLNAME$ = FIRST$ + " " + LAST$