Page "Commodore BASIC" Paragraph 16

From a modern programming point of view, the earlier versions of Commodore BASIC presented a host of bad programming traps for the programmer.

As most of these issues derived from Microsoft BASIC, virtually every home computer BASIC of the era suffered from similar deficiencies.

Every line of a Microsoft BASIC program was assigned a line number by the programmer.

It was common practice to increment numbers by some value ( 5, 10 or 100 ) to make inserting lines during program editing or debugging easier, but bad planning meant that inserting large sections into a program often required restructuring the entire code.

Later BASIC versions on Commodore and other platforms included a DELETE and RENUMBER command, as well as an AUTO line numbering command that would automatically select and insert line numbers according to a selected increment.

In addition, all variables are treated as global variables.

Clearly defined loops are hard to create, often causing the programmer to rely on the GOTO command ( this was later rectified in BASIC 3. 5 with the addition of the DO, LOOP, WHILE, UNTIL, and EXIT commands ).

Flag variables often needed to be created to perform certain tasks.

Furthermore, the 80 character line limit in earlier versions of Commodore BASIC often meant splitting tasks up into multiple routines, often resulting in spaghetti code.

Earlier BASICs from Commodore also lack debugging commands, meaning that bugs and unused variables are hard to trap.