Apple DOS - Technical Details - Integer BASIC and Applesoft Floating Point BASIC Support

Integer BASIC and Applesoft Floating Point BASIC Support

The Apple II started out using a simple BASIC interpreter known originally as Apple BASIC and later as Integer BASIC. It could only handle integer numbers ranging from -32768 to 32767 and only had built-in support for low-resolution graphics. But it was the first version of BASIC available for the Apple II and is what the earliest BASIC programs used.

Only months after the Apple II's release, Apple commissioned Microsoft to develop a much more capable interpreter known as Applesoft BASIC, capable of handling floating-point real numbers with up to nine digits of precision and base 10 multipliers from -38 to +38, and with support for high-resolution graphics. While more capable, Applesoft could not run Integer BASIC programs, causing some users to resist upgrading to it.

DOS 3.3 was released when Applesoft BASIC was standard in ROM on the Apple II Plus, so Apple designed it to support switching back and forth between the two BASIC interpreters. The DOS 3.3 System Master disk contained Integer BASIC and Applesoft on disk as a binary files which could be loaded into RAM, allowing whichever language was not resident in ROM to be used on any machine with enough RAM. The user could switch between BASICs by typing either FP or INT at either BASIC prompt. DOS automatically chose the needed language when running a saved program. Applesoft programs were saved as type A files, while Integer BASIC programs were saved as type I files.

Read more about this topic:  Apple DOS, Technical Details

Famous quotes containing the words basic, floating, point and/or support:

    What, then, is the basic difference between today’s computer and an intelligent being? It is that the computer can be made to see but not to perceive. What matters here is not that the computer is without consciousness but that thus far it is incapable of the spontaneous grasp of pattern—a capacity essential to perception and intelligence.
    Rudolf Arnheim (b. 1904)

    I know, it must have been my imagination, but it makes me realize how desperately alone the Earth is. Hanging in space like a speck of food floating in the ocean. Sooner or later to be swallowed up by some creature floating by.... Time will tell, Dr. Mason. We can only wait and wonder. Wonder how, wonder when.
    Tom Graeff. Young astronomer, Teenagers from Outer Space, after just seeing the invading spaceship through his telescope, and dismissing it (1959)

    For pain is perhaps but a violent pleasure? Who could determine the point where pleasure becomes pain, where pain is still a pleasure? Is not the utmost brightness of the ideal world soothing to us, while the lightest shadows of the physical world annoy?
    HonorĂ© De Balzac (1799–1850)

    A government which robs Peter to pay Paul can always depend on the support of Paul.
    George Bernard Shaw (1856–1950)