AppleSoft BASIC

AppleSoft BASIC. It was the primary high-level programming language for the Apple II series of home computers, succeeding the earlier Integer BASIC written by Steve Wozniak. Developed by Microsoft under contract for Apple Computer, it introduced floating-point arithmetic capabilities essential for educational and business software. Its integration into the ROM of later Apple II models made it a ubiquitous and defining feature of the platform throughout the 1980s.

History and development

The need for a more capable BASIC interpreter arose as the limitations of Integer BASIC became apparent for serious applications in fields like education and finance. In 1977, Apple Computer licensed a version of Microsoft BASIC, which was then adapted and further developed by a team including Randy Wigginton. This version, initially shipped on cassette and later disk, was known as "AppleSoft," a portmanteau of Apple and Microsoft. It was permanently embedded into the ROM of the Apple II Plus, released in 1979, cementing its role as the standard language for the platform. Subsequent models like the Apple IIe and Apple IIc continued this tradition, with minor revisions to support new hardware features such as the 80-column text display and the MouseText character set.

Language features

The language extended the core Microsoft BASIC syntax with commands tailored for the Apple II hardware. It supported floating-point numbers via a package originally from Microsoft, a significant advancement over integer-only arithmetic. Key graphics commands included `HGR` and `HGR2` for accessing the high-resolution 280x192 pixel modes, and `SHLOAD` for loading shape tables. Sound was generated via the `PEEK` and `POKE` commands to manipulate specific memory addresses controlling the built-in speaker. It also included commands for handling the game I/O annunciator ports and reading the game paddle inputs. While it lacked inherent support for structured programming, programmers often simulated procedures using `GOSUB` and `RETURN` statements.

Usage and programming environment

Upon booting an Apple II without a startup disk, the machine would typically enter the immediate mode, denoted by the `]` prompt, ready to accept commands. Programs were commonly entered line-by-line, listed with the `LIST` command, and saved to or loaded from cassette tape or 5.25-inch floppy disk using Apple DOS. The environment was entirely text-based, with programming done by memorizing commands and consulting manuals like *Apple II Reference Manual*. Despite the primitive interface, it empowered a generation of users to create everything from simple brute-force programs and educational games to complex business applications and type-in programs published in magazines such as *Nibble Magazine* and *Softalk*.

Influence and legacy

It played a foundational role in the early personal computer revolution, introducing countless users in schools and homes to programming. Its accessibility helped establish the Apple II as a dominant platform in American education throughout the 1980s. The language influenced later BASIC dialects and the design of integrated development environments. Furthermore, the deep knowledge of its inner workings, such as the call-151 monitor, fostered early software cracking and demoscene activities. Its spirit is preserved in modern retro-computing emulators like AppleWin and through active communities that continue to write new software for the classic hardware.

Example programs

A quintessential introductory program was the simple "Hello, World" variant, often extended to demonstrate the TEXT and GR graphics modes. More elaborate examples, published in periodicals, included dungeon crawler games, personal finance managers, and utilities for managing Apple DOS disks. A famous one-line program, `10 PRINT CHR$(205.5+RND(1)); : GOTO 10`, created a complex, maze-like pattern and was later analyzed in a book from the MIT Press. These programs, often shared via bulletin board systems or typed from listings, formed a vast, user-generated software library that demonstrated the language's practical capabilities and creative potential.

Category:BASIC programming language family Category:Apple II software Category:Microsoft software Category:1977 software