It was aggressively marketed through volume discounts and manufacturing arrangements to educational institutions, which made it the first computer in widespread use in American secondary schools, displacing the early leader Commodore PET.

It remained compatible with earlier Apple II models, but the IIGS has more in common with mid-1980s systems like the Atari ST, Amiga, and Acorn Archimedes.

Despite the introduction of the Motorola 68000-based Macintosh in 1984, the Apple II series still reportedly accounted for 85% of the company's hardware sales in the first quarter of fiscal 1985.

[9] Unlike preceding home microcomputers, the Apple II was sold as a finished consumer appliance rather than as a kit (unassembled or preassembled).

Apple IIs have color and high-resolution graphics modes, sound capabilities and a built-in BASIC programming language.

Over the course of the Apple II series' life, an enormous amount of first- and third-party hardware was made available to extend the capabilities of the machine.

The video controller displayed 40 columns by 24 lines of monochrome, upper-case-only (the original character set matches ASCII characters 0x20 to 0x5F) text on the screen, with NTSC composite video output suitable for display on a TV monitor, or on a regular TV set by way of a separate RF modulator.

The earliest Apple IIs were assembled in Silicon Valley, and later in Texas;[22] printed circuit boards were manufactured in Ireland and Singapore.

The Disk II interface, created by Steve Wozniak, was regarded as an engineering masterpiece for its economy of electronic components.

[citation needed] Third-party sound cards greatly improved audio capabilities, allowing simple music synthesis and text-to-speech functions.

Except for improved graphics and disk-booting support in the ROM, and the removal of the 2k 6502 assembler to make room for the floating point BASIC, the II+ was otherwise identical to the original II in terms of electronic functionality.

It was the first of three Apple II models to be made in the Snow White design language, and the only one that used its unique creamy off-white color.

[31] The Apple IIc was the first Apple II to use the 65C02 low-power variant of the 6502 processor, and featured a built-in 5.25-inch floppy drive and 128 KB RAM, with a built-in disk controller that could control external drives, composite video (NTSC or PAL), serial interfaces for modem and printer, and a port usable by either a joystick or mouse.

Two different monochrome LC displays were sold for use with the IIc's video expansion port, although both were short-lived due to high cost and poor legibility.

Its Mega II chip contains the functional equivalent of an entire Apple IIe computer (sans processor).

The OS eventually included a Macintosh-like graphical Finder for managing disks and files and opening documents and applications, along with desk accessories.

Later, the IIGS gained the ability to read and write Macintosh disks and, through third-party software, a multitasking Unix-like shell and TrueType font support.

The GS includes a 32-voice Ensoniq 5503 DOC sample-based sound synthesizer chip with 64 KB dedicated RAM,[33] 256 KB (or later 1.125 MB) of standard RAM, built-in peripheral ports (switchable between IIe-style card slots and IIc-style onboard controllers for disk drives, mouse, RGB video, and serial devices) and, built-in AppleTalk networking.

However, the video output was emulated in software, and, depending on how much of the screen the currently running program was trying to update in a single frame, performance could be much slower compared to a real IIe.

Many of the LC's built-in Macintosh peripherals could also be "borrowed" by the card when in Apple II mode, including extra RAM, the Mac's internal 3.5-inch floppy drives, AppleTalk networking, any ProDOS-formatted hard disk partitions, the serial ports, mouse, and real-time clock.

At Regis McKenna Advertising, the team assigned to launch the Apple II consisted of Rob Janoff, art director, Chip Schafer, copywriter and Bill Kelley, account executive.

A dedicated tape recorder along the lines of the Commodore Datasette was never produced; Apple recommended using the Panasonic RQ309 in some of its early printed documentation.

[47] Even after disk drives made the cassette tape interfaces obsolete they were still used by enthusiasts as simple one-bit audio input-output ports.

A commercial speech recognition Blackjack program was available, after some user-specific voice training it would recognize simple commands (Hit, stand).

Bob Bishop's "Music Kaleidoscope" was a simple program that monitored the cassette input port and based on zero-crossings created color patterns on the screen, a predecessor to current audio visualization plug-ins for media players.

A short ROM program on the disk controller had the ability to seek to track zero – which it did without regard for the read/write head's current position, resulting in the characteristic "chattering" sound of a Disk II boot, which was the read/write head hitting the rubber stop block at the end of the rail – and read and execute code from sector 0.

Most game publishers did not include DOS on their floppy disks, since they needed the memory it occupied more than its capabilities; instead, they often wrote their own boot loaders and read-only file systems.

The Apple II's slots, allowing any peripheral card to take control of the bus and directly access memory, enabled an independent industry of card manufacturers who together created a flood of hardware products that let users build systems that were far more powerful and useful (at a lower cost) than any competing system, most of which were not nearly as expandable and were universally proprietary.

[citation needed] Well into the 1990s every clean-room (the super-clean facility where spacecraft are prepared for flight) at the Kennedy Space Center used an Apple II to monitor the environment and air quality.

The album featured dance-oriented cover versions of classical music by Bach, Beethoven, and Mozart recorded directly off the Apple II motherboard.