Apple series

The following is a list of early Apple series computers, manufactured by Apple Computer.

Apple I
The Apple Computer 1, originally released as the Apple Computer in 1976, was the first computer product from the Apple Computer Company (then a partnership). It was retroactively known later as the Apple I.

It was designed and hand-built by Steve Wozniak. The idea of selling the computer came from Wozniak's friend Steve Jobs.

On March 5, 1975, Wozniak attended the first meeting of the Homebrew Computer Club in Gordon French's garage. He was so inspired that he immediately set to work on what would become the Apple I computer. He calculated that having the board design laid out would cost $1,000 and manufacturing would cost another $20 per board

The Apple I's built-in computer terminal circuitry was distinctive. All one needed to be a keyboard, television set and a cassette reader for software installation.

The first unit produced was used in a high school math class and donated to Liza Loop’s public-access computer center about 200 units were produced, and all but 25 were sold within nine or ten months.

The Apple I was sold for a list price of $666.66, which only included the motherboard. All other items were sold separately.

Apple II
Apple II, stylized as Apple ][ , is an 8-bit home computer designed primarily by Steve Wozniak. (Steve Jobs oversaw the development of the Apple II's foam-molded plastic case and Rod Holt developed the switching power supply) It was introduced by Jobs and Wozniak at the 1977 West Coast Computer Faire and was the first consumer product sold by Apple Computer.

The original retail price of the computer was US$1298  (with 4 KB of RAM) and US$2638 (with the maximum 48 kB of RAM). To reflect the computer's color graphics capability, the Apple logo on the casing was represented using rainbow stripes.

Color on the Apple II series uses a quirk of the NTSC television signal standard, which made color display relatively easy and inexpensive to implement. The original NTSC television signal specification was black-and-white. The color was added on later by adding a 3.58-megahertz subcarrier signal that was partially ignored by black-and-white TV sets. Color is encoded based on the phase’’ of this signal in relation to a reference color burst’’ signal. The result is that the position, size, and intensity of a series of pulses define color information. These pulses can translate into pixels on the computer screen, with the possibility of exploiting composite artifact colors.

The Apple II display provides two pixels per subcarrier cycle. When the color burst reference signal is turned on and the computer attached to a color display, it can display green by showing one alternating pattern of pixels, magenta with an opposite pattern of alternating pixels, and white by placing two pixels next to each other. Blue and orange are available by tweaking the offset of the pixels by half a pixel-width in relation to the color burst signal. The high-resolution display offers more colors by compressing more (and narrower) pixels into each subcarrier cycle.

The coarse, low-resolution graphics display mode works differently, as it can output a pattern of dots per pixel to offer more color options. These patterns are stored in the character generator ROM and replace the text character bit patterns when the computer is switched to low-res graphics mode. The text mode and low-res graphics mode use the same memory region and the same circuitry is used for both.

A single HGR page occupied 8 KiB of RAM; in practice, this meant that the user had to have at least 12 KiB of total RAM to use HGR mode and 20 KiB to use two pages. Early Apple II games from the 1977 to 79 period often ran only in text or low-resolution models to support users with small memory configurations; HGR not being near-universally supported by games until 1980.

Apple III
​​​​​​​The Apple III, stylized as Apple ///, is a business-oriented personal computer produced and released by Apple Computer in 1980. It was intended as the successor to the Apple II series but was largely considered a failure in the market.

Development work on the Apple III started in late 1978 under the guidance of Dr. Wendell Sander.

The machine was first announced on May 19, 1980, and released in late November that year but due to serious stability issues that required a design overhaul and a recall of existing machines, it was formally reintroduced on November 9, 1981.

Steve Wozniak and Steve Jobs expected hobbyists to purchase the Apple II, but because of VisiCalc and Disk II, small businesses purchased 90% of the computers. The Apple III was designed to be a business computer and successor. Though the Apple II contributed to the inspirations of several important business products, such as VisiCalc, Multiplan, and Apple Writer, the computer's hardware architecture, operating system, and developer environment are limited. Apple management intended to clearly establish market segmentation by designing the Apple III to appeal to the 90% business market, leaving the Apple II to home and education users. Management believed that "once the Apple III was out, the Apple II would stop selling in six months", Wozniak said.

The Apple III is powered by an 8-bit, 1.8 MHz Synertek SY6502 CPU and, like some of the later machines in the Apple II family, uses bank switching techniques to address memory beyond the 6502's traditional 64 kB limit, up to 256 kB in the III's case. Third-party vendors produced memory upgrade kits that allow the Apple III to reach up to 512 kB of random-access memory (RAM). Other Apple III built-in features include an 80-column, 24-line display with upper and lowercase characters, a numeric keypad, dual-speed (pressure-sensitive) cursor control keys, 6-bit (DAC) audio, and a built-in 140-kilobyte 5.25-inch floppy disk drive. Graphics modes include 560x192 in black and white, and 280x192 with 16 colors or shades of gray. Unlike the Apple II, the Disk III controller is part of the logic board.

he Apple III is the first Apple product to allow the user to choose both a screen font and a keyboard layout: either QWERTY or Dvorak. These choices cannot be changed while programs were running, unlike the Apple IIc, which has a keyboard switch directly above the keyboard, allowing the user to switch on the fly.

With a starting price between $4,340 to $7,800, the Apple III was more expensive than many of the CP/M-based business computers that were available at the time.