BASIC09 - Procedure Packing

Procedure Packing

Once one or more BASIC09 procedures are debugged to the programmer's satisfaction, they can be "packed" (or converted permanently to the I-code (i.e., bytecode) form) into a file. Among other things, line numbers, comments and names of local variables are discarded during packing, so that, unlike the typical interpreted BASICs of the time, comments and intelligible variable names incur no runtime cost and were therefore not a 'burden' programmers learned to avoid to maximize runtime execution time or memory efficiency. For the BASIC09 releases intended for the OS-9 operating systems, "packed" procedures are in fact OS-9 modules; the OS-9 shell recognizes them as I-code and automatically calls the RunB interpreter to execute them. RunB avoids much of the runtime overhead found in typical interpreted BASICs of the day—not to mention that one can do integer calculations where appropriate rather than doing everything in floating point—so that BASIC09 programs run extremely quickly in comparison with equivalent programs in the interpreted BASICs of the time. RunB was also smaller than nearly every other BASIC interpreter package of even remotely comparable capabilities.