||This article may contain original research. (June 2008)|
|Release date||May 1980|
|Introductory price||4,340 -$7,800|
|Operating system||Apple SOS|
|CPU||Synertek 6502A @ 2 MHz|
|Memory||128 KB, expandable to 512 KB|
The Apple III (often rendered 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 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.[unreliable source?] 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 the following autumn. Development stopped and the Apple III was discontinued on April 24, 1984, and the III Plus was dropped from the Apple product line in September 1985.
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.
Despite numerous stability issues and recalls, 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. The Apple III Plus brought this up to ~120,000. 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. 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
Apple III design 
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. The Apple III addressed these weaknesses.
The Apple III was powered by a 1.8 MHz Synertek 6502A or B 8-bit CPU and, like some of the more advanced machines in the Apple II family, used bank switching techniques to address up to 256 KB of memory. 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 display with upper and lowercase characters, a numeric keypad, dual-speed (pressure sensitive) cursor control keys, 6-bit (DAC) audio, 16-color high-resolution graphics, and a built-in 140 KB 5.25" floppy disk drive. 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.
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. 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.
Originally intended as a direct replacement to the Apple II series, it was designed for backwards-compatibility of Apple II software in order to migrate users over. However, since Apple did not want to encourage continued development of the II platform, Apple II compatibility on the Apple III 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, with no access to the III's advanced features such as its larger memory, a restriction which actually required custom chips to enforce. 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.
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, although the Apple III was able to use the Apple II's modified Disk II disk drive and vice-versa.
With the introduction of the revised Apple III a year after launch Apple began offering the ProFile external hard disk system. Costing US$3499 for 5MB, it also required a peripheral slot for the ProFile controller card.
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. The $3,495 revised model also included 256 KB RAM as a standard configuration. The 14,000 units of the original Apple III sold were returned and replaced with the entirely new revised model.
Apple III Plus 
The Apple III Plus was introduced in December 1983, while discontinuing the revised III model, at a price of US$2995. This newer version included a built-in clock, video interlacing, standardized rear port connectors, 256K RAM as standard, and a re-designed keyboard. The keyboard was designed in the style of the earlier beige Apple IIe.
Owners of the earlier Apple III could 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 
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. 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 less RFI (Radio Frequency Interference), a problem which plagued the Apple II series throughout its history. Unlike the Apple II series, the power supply was stored – 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 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.
However, many Apple III's experienced heating issues, allegedly caused by insufficient cooling and inability to dissipate the heat efficiently. To address the heat problem, later Apple III's were fitted with heat sinks. But still, the case design made it impossible for enough heat to escape. Some users stated that their Apple III became so hot that the chips started dislodging from the board, the screen would display garbled data, or their disk would come out of the slot "melted". In a technical bulletin, customers who were experiencing certain problems were instructed to lift the machine 3 inches (76 mm) and drop it in order to re-seat the chips on the logic board. Jerry Manock, the case designer, refuted these case design flaw charges and maintained that the unit adequately dissipated the internal heat, which he proved with various tests.
In the end, Manock was vindicated, as the primary culprit turned out to be 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. 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 designed by one designer on a huge drafting board, rather than a costly CAD-CAM system used for the previous board, and it worked. With normal-width traces there wasn't enough room for all of the components, so a separate daughterboard had to be designed for the RAM which would fit within the existing heatsink.
Earlier Apple III units came with a built-in real time clock, manufactured by National Semiconductor. The hardware, however, would fail after prolonged use. While it was assumed that a vendor would test 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 sold the peripheral as a level 1 technician add-on.
Commercial failure 
For a variety of reasons, the Apple III was a commercial failure. With a starting price between $4,340 to $7,800 US, it was more expensive than many of the CP/M-based business computers that were available at the time. The Apple III's software library was very limited, and while sold as Apple II compatible, the emulation that made this possible was intentionally hobbled; thus it could not make use of the advanced III features (specifically 64 KB RAM or higher, required by a large number of Apple II software titles based on PASCAL), which limited its usefulness.
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 wasn't until several months after the Apple III was introduced that native 80-column business software became available.
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.
See also 
- VAW: Pre-PowerPC Profile Specs
- Two Apple Failures: Apple III and Lisa[unreliable source?]
- Apple III computer @ oldcomputers.net
- Linzmayer, Owen W. Apple Confidential 2.0: The Definitive History of the World's Most Colorful Company. pp. 41–43. ISBN 1-59327-010-0.
- The Origin of the IBM PC
- 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.
- The Apple III Project
- "Apple Panic?".
- Beneath Apple DOS, Chapter 6 Using DOS from Assembly Language
- Apple III @ bott.org
- First Cool, Now Quiet
- Computer History Museum: Apple Industrial Designers Robert Brunner and Jerry Manock
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