BASIC is a high-level programming language that is an extension of the Dartmouth BASIC (Beginners All-purpose Symbolic Instruction Code) language. It is the principal programming language bundled with the D3 system and was designed for the implementation of application requirements not inherent in standard D3 functionality.

BASIC source can contain any number of statements in any order and can be stored as source programs or subroutines called by other programs, processing codes or VB modules. BASIC programs are created an editor of choice and reside as item within a data file.

Prior to execution, the programs must be compiled to convert the source program into object code. Compiled object items are stored in the dictionary of the data file that contains the source code. Compiled programs can be cataloged as commands within the master dictionary. Subroutines must be cataloged as commands within the master dictionary.

BASIC source code can be compiled in the traditional way, or it can be optimized or flashed.