Integer BASIC

Integer BASIC was the first version of BASIC available for the Apple II series of computers. It was written by Steve Wozniak in 6502 assembly.

It is named Integer BASIC because it did not have any floating point capabilities and worked only with signed 16-bit integers.

The Integer BASIC ROMs also included a "mini-assembler" that let programmers type assembly language programs, line by line, which were entered into memory. This was of course far easier than looking up the corresponding opcodes in machine language and typing those in. These ROMs also included an interpreter for a 16-bit bytecode language, called Sweet16, which was very simple, compact and worthy of study. These two features, some cassette tape I/O routines, and a few seldom-used floating point math routines were removed in the transition from the Integer BASIC ROMs to the Apple II+ ROMs, in order to accommodate the larger size of the Applesoft BASIC interpreter.

When running Apple DOS, it was possible to switch between Applesoft BASIC and Integer BASIC by typing either INT (to enter Integer BASIC) or FP (to enter Applesoft BASIC) (though as noted above, later Apples needed to have Integer BASIC loaded into memory first). The command line symbol for Integer Basic was a right-facing arrow ( > ).

External Links

• An Integer BASIC Reference