Commodore Plus 4 - Page 181

SECTION 3 Converting Standard BASIC Programs To Commodore BASIC 3.5
Conversion
Programs
If you have programs written in a BASIC other than Commodore
BASIC, some minor adjustments may be necessary before
running them on the Plus/4. Here are some hints to make the
conversions easier.
String Dimensions
Delete all statements that are used to declare the length of strings.
A statement such as DIM A$(l,J), which DIMensions a string array
for J elements of length I, should be converted to the Commodore
BASIC statement DIM A${J).
Some BASICS use a comma or ampersand for string concatenation
(linking). Each of these must bexhanged to a + sign, which is the
Commodore BASIC 3.5 operator for string concatenation.
In Commodore BASIC, the MIDS. RIGHTS, and LEFTS functions are
used to lake substrings of strings. Forms such as A$(l) to access the
Ith character in AS, or AS(I.J) to take a substring of AS from position
I to J, must be changed as follows:
Other BASIC
A$(l) - XS
AS(I.J) = XS
Commodore BASIC 3.5
MIDS(AS,I.J) = X$
MID$(A$,I,J) = X$
Multiple Assignments
To set B and C equal to zero, some BASICs allow statements of the
form: 10 LET B- C =0
Commodore BASIC would interpret the second sign as a logical
operator and set B = -1 if C = 0. Instead, convert this statement to:
10C = 0 B = 0
Multiple Statements
Some BASICs use a backslash (/) to separate multiple statements on a
line. With 3.5 BASIC, use a colon (:) to separate all statements.
Mat Functions
Programs using the MAT functions available on some BASICs must be
rewritten using FOR.. .NEXT loops to execute properly.
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