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Apple III

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Title: Apple III  
Author: World Heritage Encyclopedia
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Subject: Timeline of Apple Inc. products, Apple Lisa, Macintosh External Disk Drive, Apple II Plus, Apple II series
Collection: Apple II Family, Apple Inc. Hardware, Products Introduced in 1980
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Apple III

Apple III
Release date May 1980 (1980-05)
Introductory price 4340 US$ - 7800 US$ (today $12422.29 - $22325.77)[1]
Discontinued April 1984 (1984-04)
Operating system Apple SOS
CPU Synertek 6502A @ 2 MHz
Memory 128 KB, expandable to 512 KB

The Apple III (often styled as Apple ///) is a business-oriented personal computer produced and released by Apple Computer that 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. It had the internal code name of "Sara", named after Sander's daughter.[2] The machine was first announced and released on May 19, 1980, but due to serious stability issues that required a design overhaul and a recall of existing machines, it was formally reintroduced in the second half of 1981.[3] Development stopped and the Apple III was discontinued on April 24, 1984, and its last successor—the III Plus, was dropped from the Apple product line in September 1985.[4]

The Apple III could be viewed as an enhanced Apple II – then the newest heir to a line of 8-bit machines dating back to 1976. However, the Apple III was not part of the Apple II line, but rather a close cousin. The key features business users wanted in a personal computer were a true typewriter-style upper/lowercase keyboard (as opposed to the Apple II which was based on a Teletype keyboard) and 80-column display. In addition, the machine had to pass U.S. Federal Communications Commission (FCC) Radio Frequency Interference (RFI) qualifications for business equipment. In 1981, International Business Machines unveiled the IBM Personal Computer (IBM PC) – a completely new 16-bit design soon available in a wide range of inexpensive clones. The business market moved rapidly towards the PC DOS/MS-DOS platform, eventually pulling away from the Apple 8-bit computer line.[5]

Despite numerous stability issues and a recall that included the first 14,000 units off the assembly line, Apple was eventually able to produce a reliable and dependable version of the machine. However, damage to the computer's reputation had already been done and it failed to do well commercially as a direct result. In the end, an estimated 65,000–75,000 Apple III computers were sold.[3][4] The Apple III Plus brought this up to ~120,000.[4] Apple co-founder Steve Wozniak stated that the primary reason for the Apple III's failure was that the system was designed by Apple's marketing department, unlike Apple's previous engineering-driven projects.[6] The Apple III's failure led to Apple reevaluating their plan to phase out the Apple II, and eventual continuation of development of the older machine. As a result, later Apple II models incorporated some hardware, such as the Apple Scribe Printer, a thermal printer, and software technologies of the Apple III.


  • Timeline of Apple II family models 1
  • Design 2
  • Software 3
  • Peripherals 4
  • Revisions 5
    • Apple III Plus 5.1
  • Design flaws 6
  • Commercial failure 7
  • Influence 8
  • In Popular Culture 9
  • See also 10
  • References 11
  • External links 12

Timeline of Apple II family models


The Apple III was designed to be a business computer and an eventual successor for the Apple II. While 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 were limited.[7] The Apple III addressed these weaknesses. According to Steve Wozniak, VisiCalc and Disk II had caused the Apple II's popularity, with 90% of sales going to businesses as opposed to the hobbyists that were its original market. Apple management intended to clearly establish market segmentation by designing the Apple III to appeal to the 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.[8]

The Apple III was powered by a 1.8 MHz Synertek 6502A or B[9] 8-bit CPU and, like some of the later machines in the Apple II family, used bank switching techniques to address memory beyond the 6502's traditional 64KB limit, up to 256 K in the IIIs case. Third-party vendors also produced memory upgrade kits that allowed the Apple III to reach up to 512 KB. Other Apple III built-in features included 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 KB 5.25" floppy disk drive. Graphics modes included 560x192 in black and white, and 280x192 with 16 colors or shades of gray. Unlike the Apple II, the Disk III controller was built into the logic board.

The Apple III was the first Apple product that allowed the user to choose both a screen font and a keyboard layout: either QWERTY or Dvorak. These choices could not be changed while programs were running, unlike the Apple IIc, which had a keyboard switch directly above the keyboard, allowing switching on the fly.


An advertisement for access to health information through the Apple III

A major limitation of the Apple II and DOS 3.3 was the way it addressed resources, which made it highly desirable for peripherals to be installed in standardized locations (slot 5 and 6 reserved for storage devices, slot 2 reserved for serial communication interfaces, etc.) This forced the user to identify a peripheral by its physical location, such as PR#6, CATALOG, D1, and so on.[10] The Apple III introduced an advanced operating system called Apple SOS, pronounced "apple sauce". Its ability to address resources by name instead of a physical location allowed the Apple III to be more scalable. Apple SOS also allowed the full capacity of a storage device to be used as a single volume, such as the Apple ProFile hard disk drive. Also, Apple SOS supported a hierarchical file system (HFS). Some of the features and code base of Apple SOS made their way into the Apple II's ProDOS and GS/OS operating systems, as well as Lisa 7/7 and Macintosh system software.

The Apple III also introduced a new BASIC interpreter called Apple III Business BASIC, and later an implementation of UCSD Pascal for more structured programming.

With a starting price between $4,340 to $7,800 US, the Apple III was more expensive than many of the CP/M-based business computers that were available at the time.[1] Little Apple III software was available besides VisiCalc, and because Apple did not view the Apple III as suitable for hobbyists, it did not provide much of the technical software information that accompanied the Apple II.[11] Originally intended as a direct replacement to the Apple II series, it was designed to be backwards compatible with Apple II software. However, since Apple did not want to encourage continued development of the II platform, Apple II compatibility existed only in a special "Apple II Mode" which was limited in its capabilities to the emulation of a basic 48 KB Apple II+ configuration. Special chips were intentionally added to prevent access to the III's advanced features such as its larger memory.[8]

Early Apple III users were told that they had to use existing 40-column Apple II word processors and spreadsheet programs, which hurt sales since those programs could be used in 80-column mode on the Apple IIs with the suitable hardware installed. It was not until several months after the Apple III was introduced that native 80-column business software became available. Since many business-oriented Apple II programs started requiring at least 64 KB of RAM (i.e. an 48 KB Apple II with an added 16 KB "language card") around the time the III was released, they were incompatible with the III, preventing some users from switching over.

The Apple III had a System Utilities program, which allowed system reconfiguration and file manipulation. Another program, Selector III, was designed to integrate with the System Utilities program and launch various applications. The program was developed by ON THREE, a large Apple III user group. Another company, Quark Software, developed a competing product, Catalyst, the cruder interface of which was offset by program-switching capabilities and support for copy-protection, which enabled companies to license users to run programs from a hard disk without worrying that their software might be backed up or copied without permission. When Apple decided to bundle Catalyst with its new ProFile hard disk, Quark celebrated, but ON THREE continued to market and sell Selector III through their monthly magazine. Selector III remained commercially available and supported long after Quark discontinued its Apple III product line.


The Apple III had four expansion slots, a number that inCider in 1986 called "miserly".[12] Apple II cards were compatible but risked violating government RFI regulations, and required Apple III-specific device drivers; BYTE stated that "Apple provides virtually no information on how to write them". As with software, Apple provided little hardware technical information with the computer[11] but Apple III-specific products became available, such as one that made the computer compatible with the Apple IIe.[12] Several new Apple-produced peripherals were developed for the Apple III. The original Apple III came with a built-in real-time clock, which was recognized by Apple SOS. The clock was later removed from the "revised" model, and instead was made available as an add-on.

Along with the built-in floppy drive, the Apple III could also handle up to three additional external Disk III floppy disk drives. The Disk III was only officially compatible with the Apple III. The Apple III Plus required an adapter from Apple to use the Disk III with its DB-25 disk port. [13]

With the introduction of the revised Apple III a year after launch Apple began offering the ProFile external hard disk system.[14] Costing US$3499 for 5MB, it also required a peripheral slot for the ProFile controller card.


Apple III Plus

Once the logic board design flaws were discovered, a newer logic board design was produced – which included a lower power requirement, wider traces and better designed chip sockets.[14] The $3,495 revised model also included 256 KB RAM as a standard configuration.[14] The 14,000 units of the original Apple III sold were returned and replaced with the entirely new revised model.

Apple III Plus

Apple discontinued the III in October 1983 because it violated Federal Communications Commission (FCC) regulations, and the FCC required the company to change the redesigned computer's name.[15][16] It introduced the Apple III Plus in December 1983 at a price of US$2995. This newer version included a built-in clock, video interlacing, standardized rear port connectors, 55-watt power supply, 256K RAM as standard, and a redesigned, IIe-like keyboard.[14][16]

Owners of the Apple III could purchase individual III Plus upgrades, like the clock and interlacing feature,[16] and obtain the newer logic board as a service replacement. A keyboard upgrade kit, dubbed "Apple III Plus upgrade kit" was also made available – which included the keyboard, cover, keyboard encoder ROM and logo replacements. This upgrade had to be installed by an authorized service technician.

Design flaws

According to Wozniak, the Apple III "had 100 percent hardware failures".[8] Former Apple executive Taylor Pohlman recalled:[17]

There was way too short a time frame in manufacturing and development. When the decision was made to announce, there were only three Apple IIIs in existence, and they were all wire-wrapped boards. The case of the Apple III had long since been set in concrete, so they had a certain size logic board to fit the circuits on ... They went to three different outside houses and nobody could get a layout that would fit on the board. They used the smallest line circuit boards that could be used. They ran about 1,000 of these boards as preproduction units to give to the dealers as demonstration units. They really didn't work ... Apple swapped out the boards. The problem was, at this point there were other problems, things like chips that didn't fit. There were a million problems that you would normally take care of when you do your preproduction and pilot run. Basically, customers were shipped the pilot run.

Steve Jobs insisted on the idea of no fan or air vents – in order to make the computer run quietly. Jobs would later push this same ideology onto almost all Apple models he had control of – from the Apple Lisa and Macintosh 128K to the iMac.[18] To allow the computer to dissipate heat, the base of the Apple III was made of heavy cast aluminum, which supposedly acted as a heat sink. One undeniable advantage to the aluminum case was a reduction in RFI (Radio Frequency Interference), a problem which had plagued the Apple II series throughout its history. Unlike the Apple II series, the power supply was mounted – without its own shell – in a compartment separate from the logic board. The decision to use an aluminum shell ultimately led to engineering issues which resulted in the Apple III's reliability problems. The lead time for manufacturing the shells was high, and this had to be done before the motherboard was finalized. Later it was realized that there wasn't enough room on the motherboard for all of the components unless narrow traces were used.

Apple III Plus showing the RFI shield over the floppy drive and the cast aluminum case

Many Apple IIIs were thought to have failed due to their inability to properly dissipate heat. inCider stated in 1986 that "Heat has always been a formidable enemy of the Apple ///",[12] and some users reported that their Apple IIIs became so hot that the chips started dislodging from the board, causing the screen to display garbled data or their disk to come out of the slot "melted". BYTE wrote, "the integrated circuits tended to wander out of their sockets".[11] Apple advised customers to lift the Apple III off the desk until it was six inches in the air, and then drop it to reseat the chips.[4] Other analyses blame a faulty automatic chip insertion process, not heat.[19]

Case designer Jerry Manock denied the design flaw charges, stating that tests proved that the unit adequately dissipated the internal heat. The primary cause, he claimed, was a major logic board design problem. The logic board used "fineline" technology that was not fully mature at the time, with narrow, closely spaced traces.[20] When chips were "stuffed" into the board and wave-soldered, solder bridges would form between traces that were not supposed to be connected. This caused numerous short circuits, which required hours of costly diagnosis and hand rework to fix. Apple designed a new circuit board, with more layers and normal-width traces. The new logic board was laid out by one designer on a huge drafting board, rather than using the costly CAD-CAM system used for the previous board, and the new design worked.

Earlier Apple III units came with a built-in real time clock. The hardware, however, would fail after prolonged use.[11] Assuming that National Semiconductor would test all parts before shipping them, Apple did not perform this level of testing. Apple was soldering chips directly to boards, and could not easily change out a bad chip if one was found. Eventually, Apple solved this problem by removing the real-time clock from the Apple III's specification rather than shipping the Apple III with the clock pre-installed, and then sold the peripheral as a level 1 technician add-on.[4]

Commercial failure

Pohlman stated that Apple was only selling 500 units a month by late 1981, mostly as replacements. The company was able to raise monthly sales to 5,000, but the IBM PC's successful launch encouraged software companies to develop for it instead, causing Apple to shift focus to the Lisa and Macintosh.[17] By early 1984 sales were only to existing III owners, Apple itself—its 4500 employees had about 3000-4500 units—and some small businesses.[16][15] Despite formerly devoting the majority of its R&D to the III and so ignoring the II that for a while dealers had difficulty in obtaining the latter,[21] Apple discontinued the Apple III series on 24 April 1984, four months after introducing the III Plus, after selling 65-75,000 computers and replacing 14,000 defective units.[22]

Jobs stated that Apple lost "infinite, incalculable amounts" of money on the Apple III.[22] Pohlman claimed that there was a "stigma" at the company associated with having contributed to the computer. Most employees who worked on the III reportedly left Apple.[17]


The filesystem and some design ideas from Apple SOS, the Apple III's operating system, were part of Apple ProDOS and Apple GS/OS, the major operating systems for the Apple II series following the demise of the Apple III, as well as the Apple Lisa, which was the de facto business-oriented successor to the Apple III. The hierarchical file system influenced the evolution of the Macintosh: while the original Macintosh File System (MFS) was a flat file system designed for a floppy disk without subdirectories, subsequent file systems were hierarchical. By comparison, the IBM PC's first file system (again designed for floppy disks) was flat; likewise, later versions (designed for hard disks) were hierarchical.

In Popular Culture

At the start of the Walt Disney Pictures film TRON, lead character Kevin Flynn (played by Jeff Bridges) is seen hacking into the ENCOM mainframe using an Apple III.[23]

See also


  1. ^ a b VAW: Pre-PowerPC Profile Specs
  2. ^ Linzmayer, Owen W. (2004). Apple Confidential 2.0: The Definitive History of the World's Most Colorful Company, No Starch Press. ISBN 9781593270100. p41.
  3. ^ a b Apple III computer @
  4. ^ a b c d e
  5. ^ The Origin of the IBM PC
  6. ^ Wozniak, S. G. (2006), iWoz: From Computer Geek to Cult Icon: How I Invented the Personal Computer, Co-Founded Apple, and Had Fun Doing It. W. W. Norton & Company. ISBN 0-393-06143-4.
  7. ^ The Apple III Project
  8. ^ a b c
  9. ^
  10. ^ Beneath Apple DOS, Chapter 6 Using DOS from Assembly Language
  11. ^ a b c d
  12. ^ a b c
  13. ^
  14. ^ a b c d Apple III @
  15. ^ a b
  16. ^ a b c d
  17. ^ a b c
  18. ^ First Cool, Now Quiet
  19. ^
  20. ^ Computer History Museum: Apple Industrial Designers Robert Brunner and Jerry Manock
  21. ^
  22. ^ a b
  23. ^

External links

  • Inside the Apple III
  • The Ill-Fated Apple III
  • Many manuals and diagrams
  • Sara – Apple /// emulator
Preceded by
Apple II
Apple III
May 1980
Succeeded by
Apple III Plus
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