[11] The earliest Apple II computers were assembled in Silicon Valley and later in Texas;[16] printed circuit boards were manufactured in Ireland and Singapore.

The first computers went on sale on June 10, 1977[17][18] with an MOS Technology 6502 microprocessor running at 1.023 MHz (2⁄7 of the NTSC color subcarrier), two game paddles[19] (bundled until 1980, when they were found to violate FCC regulations),[20] 4 KiB of RAM, an audio cassette interface for loading programs and storing data, and the Integer BASIC programming language built into ROMs.

The original retail price of the computer with 4 KiB of RAM was US$1,298 (equivalent to $6,530 in 2023)[21] and with the maximum 48 KiB of RAM, it was US$2,638 (equivalent to $13,260 in 2023)[22] To reflect the computer's color graphics capability, the Apple logo on the casing has rainbow stripes,[23] which remained a part of Apple's corporate logo until early 1998.

Perhaps most significantly, the Apple II was a catalyst for personal computers across many industries; it opened the doors to software marketed at consumers.

"[26] In the May 1977 issue of Byte, Steve Wozniak published a detailed description of his design; the article began, "To me, a personal computer should be small, reliable, convenient to use, and inexpensive.

"[27] The Apple II used peculiar engineering shortcuts to save hardware and reduce costs, such as: The text and graphics screens have a complex arrangement.

This complexity was reportedly due to Wozniak's realization that the method would allow for the refresh of dynamic RAM as a side effect (as described above).

This method had no cost overhead to have software calculate or look up the address of the required scanline and avoided the need for significant extra hardware.

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

With a few small-scale logic chips and a cheap PROM (programmable read-only memory), he created a functional floppy disk interface at a fraction of the component cost of standard circuit configurations.

[31] In addition, the initial case design had no vent openings, causing high heat buildup from the PCB and resulting in the plastic softening and sagging.

The Apple II's printed circuit board (PCB) underwent several revisions, as Steve Wozniak made modifications to it.

Revision 0 Apple IIs powered up in an undefined mode and had garbage on-screen, requiring the user to press Reset.

Unlike most machines, all integrated circuits on the Apple II PCB were socketed; although this cost more to manufacture and created the possibility of loose chips causing a system malfunction, it was considered preferable to make servicing and replacement of bad chips easier.

The coarse, low-resolution graphics display mode works differently, as it can output a pattern of dots per pixel to offer more color options.

Rather than a dedicated sound-synthesis chip, the Apple II contains a toggle circuit that can only emit a click through a built-in speaker or a line-out jack.

More complex sounds, such as music or audio samples, are generated by software manually toggling the speaker at an appropriate frequency.

This technique requires careful and precise timing, rendering it difficult to display moving graphics while sound is playing.

Written by Wozniak, the interpreter enabled users to write software applications without needing to purchase additional development utilities.

Written with game programmers and hobbyists in mind, the language only supported the encoding of numbers in 16-bit integer format.

Because Steve Wozniak was busy developing the Disk II hardware, he did not have time to modify Integer BASIC for floating point support.

Apple also offered a different version of Applesoft for cassette users, which occupied low memory, and was started by using the LOAD command in Integer BASIC.

An Apple II manual signed by Steve Jobs in 1980 with the inscription "Julian, your generation is the first to grow up with computers.

Wozniak's open-architecture design and Apple II's multiple expansion slots permitted a wide variety of third-party devices, including peripheral cards, such as serial controllers, display controllers, memory boards, hard disks, networking components, and real-time clocks.

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

Early Apple IIs were often sold with a Sup'R'Mod, which allowed the composite video signal to be viewed in a television.

But the company also had "to negotiate the attitudes of its potential buyers, bearing in mind social anxieties about the uptake of new technologies in multiple contexts.

"[41] After seeing a crude, wire-wrapped prototype demonstrated by Wozniak and Steve Jobs in November 1976,[19] Byte predicted in April 1977, that the Apple II "may be the first product to fully qualify as the 'appliance computer' ... a completed system which is purchased off the retail shelf, taken home, plugged in and used".

"[19] Personal Computer World in August 1978 also cited the color capability as a strength, stating that "the prime reason that anyone buys an Apple II must surely be for the colour graphics".

While mentioning the "oddity" of the artifact colors that produced output "that is not always what one wishes to do", it noted that "no-one has colour graphics like this at this sort of price".