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| - Applesoft BASIC was a dialect of BASIC supplied on the Apple II computer, superseding Integer BASIC. Applesoft BASIC was supplied by Microsoft and its name is derived from the names of both Apple and Microsoft. The first version of Applesoft was released in 1977 only on cassette tape and lacked support for high-resolution graphics. Applesoft II, which was made available on cassette and disk and in the ROM of the Apple II Plus and subsequent models, was released in 1978. It is this latter version, which has some syntax differences from the first as well as support for the Apple II high-resolution graphics modes, that most people mean by the term "Applesoft." Apple's customers were demanding a version of BASIC that supported floating point calculations. As Steve Wozniak, the creator of Integer BASIC and the only person who understood it well enough to add floating point features, was busy with the Disk II drive and controller and with Apple DOS, Apple turned to Microsoft, who was the BASIC vendor of choice after their success with Altair BASIC, and licensed a 10 KB assembly language version of BASIC dubbed "Applesoft." Apple reportedly obtained an eight-year license for Applesoft BASIC from Microsoft for a flat fee of $31,000, renewing it in 1985 through an arrangement that gave Microsoft the rights and source code for Apple's Macintosh version of BASIC. Applesoft was similar to (and indeed had a common code base with) BASIC implementations on other 6502-based computers, such as Commodore BASIC: it used line numbers, and spaces were not necessary in lines. While Applesoft was slower than Integer BASIC, it had many features that the older BASIC lacked: Atomic strings. A string is no longer an array of characters; it is instead a garbage-collected object . This allows for string arrays; DIM A$ resulted in a vector of eleven string variables numbered 0 to 10. Multidimensional arrays. Single-precision floating point variables with an 8-bit exponent and a 31-bit significand and improved math capabilities, including trigonometry and logarithmic functions. Commands for high-resolution graphics. CHR$, ASC, STR$, and VAL functions for converting between string and numeric types LET statement optional User defined functions Error-trapping, allowing BASIC programs to handle unexpected errors by means of a subroutine written in BASIC. PEEK and POKE commands that let the user read the contents of a memory location or stuff a numeric value into any desired memory location. Whereas Wozniak originally referred to his Integer BASIC as "Game BASIC," having written it so he could write a Breakout game for his new computer, few action games were written in Applesoft BASIC for several reasons: In this era of carefully counting clock cycles and limited memory, it was inefficient to write speed-dependent programs that ran on a runtime interpreter. The use of real numbers for all math operations created unnecessary overhead and degraded performance. Applesoft converted integer numbers to real before performing operations on them, converting the result back to an integer only if it was to be assigned to a integer variable. So-called shape tables are a slow alternative to bitmaps. No provision existed for mixing text and graphics, except for the limited "Hardware split screen" of the Apple II . Many graphics programs thus contained their own bitmap character generator routines. No provision was added in the 128 KB Apple IIe and Apple IIc models' BASIC interpreters for the new machines' extra memory and double-resolution graphics, or for the Apple II's 16-color mode. The program was stored as a linked list of lines; a GOTO took O time, and although Applesoft programs were not very long compared to today's software, on a 1 MHz 6502 this could be a significant bottleneck. No sound support aside from a PEEK command that could be used to click the speaker . The language was not fast enough to produce more than a baritone buzz from repeated clicks anyway. However, music spanning several octaves could be played by repeated calls to a machine-language tone generator. Here's Hello World in Applesoft BASIC: 10 TEXT:HOME 20 ?"HELLO WORLD" Multiple commands could be included on the same line of code if separated by a colon . The ? can be used in Applesoft BASIC as a shortcut for "PRINT", though spelling out the word is not only acceptable but canonical -- Applesoft converted "?" in entered programs to "PRINT", which would appear when a program was listed. So the program above would actually appear in a LIST command as shown below: 10 TEXT : HOME 20 PRINT "HELLO WORLD" This article includes text from Everything2, licensed under GFDL. (en)
- Applesoft BASIC (manchmal auch "Applesoft II" genannt) war die zweite Version der Programmiersprache BASIC für den Apple II Homecomputer, die dem Integer BASIC folgte. Applesoft BASIC wurde von Microsoft entwickelt, und der Produktname entstand aus den beiden Firmennamen Apple und Microsoft. Applesoft BASIC kann auf dem frühesten Modell der Apple-II-Serie, dem eigentlichen Apple II, von einem Datenträger ins RAM geladen oder als ROM-Steckkarte hinzugefügt werden. In allen späteren Modellen der Serie -- dem Apple II+, Apple IIe, Apple IIc, Apple IIgs und Apple IIc+ -- ist es als ROM fest eingebaut und steht damit sofort nach dem Einschalten zur Verfügung. Die Applesoft-Versionen der einzelnen Modelle unterscheiden sich nur minimal, insbesondere unterstützt keine davon die Verwendung von mehr als 48 KB RAM für BASIC-Programme, auch nicht in den Modellen, die von Haus aus wesentlich mehr RAM-Speicher mitbringen. (de)
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