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. 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.
Other Apple III built-in features include an column, 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 KB 5. Graphics modes include x in black and white, and x with 16 colors or shades of gray. The Apple III is the first Apple product to allow the user to choose both a screen font and a keyboard layout: 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.
Apple SOS also allows the full capacity of a storage device to be used as a single volume, such as the Apple ProFile hard disk drive. Special chips were intentionally added to prevent access to the III's advanced features such as its larger memory.
As with software, Apple provided little hardware technical information with the computer  but Apple III-specific products became available, such as one that made the computer compatible with the Apple IIe. The clock was later removed from the "revised" model, and was instead made available as an add-on. Revisions[ edit ] Apple III Plus Once the logic board design flaws were discovered, a newer logic board design was produced — which includes a lower power requirement, wider traces, and better-designed chip sockets.
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. 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, 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 K to the iMac.
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.
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.
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. 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.
Ed Smith, who after the APF Imagination Machine became a distributor's representative, described the computer as "a complete disaster". The company was able to raise monthly sales to 5,, 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. Most employees who worked on the III reportedly left Apple. The hierarchical file system influenced the evolution of the Macintosh: By comparison, the IBM PC 's first file system again designed for floppy disks was also flat and later versions designed for hard disks were hierarchical.