Editing Apple III

{{Short description|Business-oriented personal computer made by Apple Computer}}
{{Multiple issues|{{More citations needed|date=April 2023}}
{{Original research|date=April 2023}}}}
{{Use mdy dates|date=October 2013}}
{{Infobox computing device
| name = Apple III
| logo = Apple III logo.svg
| image = Apple3.jpg
| caption = 
| developer = [[Apple Computer]]
| family = 
| type = 
| releasedate = {{Start date and age|1980|11}}{{sfn|Linzmayer|2004|pp=42-43}}
| price = {{nowrap|[[United States dollar|US$]]4,340}} – {{nowrap|$7,800}} (equivalent to {{nowrap| ${{Inflation|US|4340|1980|r=-1|fmt=c}} –}} {{nowrap| ${{Inflation|US|7800|1980|r=-1|fmt=c}} in {{Inflation/year|US}})}}<ref name="avuqmb">[http://www.vectronicsappleworld.com/profiles/84.html VAW: Pre-PowerPC Profile Specs] {{webarchive |url=https://web.archive.org/web/20080213001831/http://www.vectronicsappleworld.com/profiles/84.html |date=February 13, 2008 }}</ref>
| discontinued = {{End date and age|1984|4|24}}
| unitssold = 65,000–75,000
| unitsshipped = 
| os = [[Apple SOS]]
| power = 
| cpu = [[Synertek]] [[MOS Technology 6502|6502]]B @ 1.8 &nbsp;MHz<ref>https://archive.org/details/Apple_3_Data_Sheet_A3/mode/2up</ref>
| memory = {{nowrap|128 [[Kilobyte|KB]]}} of RAM, expandable to {{nowrap|512 KB}}
| display = 80×24 text<br />560×192 pixels (monochrome)<br />280×192 pixels (16 colors or grayscale)
| graphics = 
| sound = 6-bit DAC
| input = 
| dimensions = 
| weight = 
| predecessor = [[Apple II]]
| successor = [[Apple III Plus]]
| memory card = {{frac|5|1|4}} inch [[floppy disk]]
}}

The '''Apple III''' (styled as '''apple ///''') is a business-oriented personal computer produced by [[Apple Computer]] and released in 1980. Running the [[Apple SOS]] operating system, it was intended as the successor to the [[Apple II]]; however, it was largely considered a failure in the market. It was designed to provide features business users wanted: a true typewriter-style keyboard with upper and lowercase letters (the Apple II only supported uppercase at the time) and an 80-column display.

It had the internal code name of "Sara", named after Wendell Sander's daughter.{{sfn|Linzmayer|2004|pp=41–43}} The system was announced on May 19, 1980, and released in late November that year.{{sfn|Linzmayer|2004|pp=41–42}} Serious stability issues required a design overhaul and a recall of the first 14,000 machines produced. The Apple III was formally reintroduced on November 9, 1981.{{sfn|Linzmayer|2004|pp=41–42}}<ref name = "intro">{{cite web|first=Steven|last=Stenger|url=http://oldcomputers.net/appleiii.html|title=Apple III|website=oldcomputers.net|access-date=August 1, 2009|archive-date=November 24, 2021|archive-url=https://web.archive.org/web/20211124121927/http://www.oldcomputers.net/appleiii.html|url-status=live}}</ref>{{Better source needed|date=November 2019}}

Damage to the computer's reputation had already been done, however, and it failed to do well commercially. Development stopped, and the Apple III was discontinued on April 24, 1984. Its last successor, the III Plus, was dropped from the Apple product line in September 1985.{{sfn|Linzmayer|2004|pp=41–43}}

An estimated 65,000 to 75,000 Apple III computers were sold.<ref name = "intro" />{{sfn|Linzmayer|2004|pp=41–43}} The Apple III Plus brought this up to approximately 120,000.{{sfn|Linzmayer|2004|pp=41–43}} 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.<ref name="iwoz">{{cite book|author-link=Steve Wozniak|last=Wozniak|first=S. G.|year=2006|title=iWoz: From Computer Geek to Cult Icon: How I Invented the Personal Computer, Co-Founded Apple, and Had Fun Doing It|url=https://archive.org/details/iwozcomputergeek00wozn|url-access=registration|publisher=[[W. W. Norton & Company]]|isbn=0-393-06143-4|oclc=502898652}}</ref> The Apple III's failure led Apple to reevaluate its plan to phase out the Apple II, prompting the eventual continuation of development of the older machine. As a result, later Apple II models incorporated some hardware and software technologies of the Apple III.

==Overview==
===Design===
[[Steve Wozniak]] and [[Steve Jobs]] expected hobbyists to purchase the Apple II; however, because of [[VisiCalc]] and [[Disk II]], small businesses purchased 90% of the computers.{{r|byte198501}} 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.<ref name="apple2hist">{{Cite web |title=The Apple III SOS Reference Manual Vol 1 |url=https://archive.org/details/apple-iii-sos-reference-manual-vol-1/page/n40/mode/1up |url-status=dead |archive-url= |archive-date= |access-date= |website=Internet Archive}}</ref> 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.<ref name="byte198501">{{cite magazine |title=The Apple Story / Part 2: More History and the Apple III |magazine=[[Byte (magazine)|BYTE]] |publisher=UBM Technology Group|location=United States|volume=10|number=1|issn=0360-5280|oclc=637876171|date=January 1985 |author-last1=Williams |author-first1=Gregg |author-last2=Moore |author-first2=Rob |page=167 |type=interview |url=https://archive.org/details/198501_byte_magazine_vol_10_01_through_the_hourglass_pdf__mlib/page/174/mode/2up}}</ref>

The Apple III is powered by a 2 [[megahertz]] [[Synertek]] [[MOS Technology 6502|6502A]] or 6502B<ref>{{cite book |author1= |title=Apple III Owner's Guide |author2= |publisher=Apple Computer Inc. #A3L0001 |year=1981 |edition=3rd |pages=152–153 |language=English}}</ref><ref>{{Cite book |title=Apple III Benutzer Handbuch |publisher=[[Apple Inc.|Apple Computer International]] |year=1981 |pages=151 |language=de |trans-title=Apple III User Manual}}</ref>  [[8-bit]] [[central processing unit|CPU]] (operating effectively between 1.4 and 1.8&nbsp;MHz due to video or memory refresh cycles) 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&nbsp;KB limit, up to 256&nbsp;KB in the III's case. Third-party vendors produced memory upgrade kits that allow the Apple III to reach up to 512&nbsp;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 ([[digital-to-analog converter|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 [[disk controller|controller]] is part of the logic board.

The 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 keyboard layout|Dvorak]]. These choices cannot be changed while programs were running. This was unlike the [[Apple IIc]], which has a keyboard switch directly above the keyboard, allowing the user to switch on the fly.

===Software===
[[File:Desktop Computer - The Future for Medicine (FDA 095) (8249708093).jpg|thumb|An advertisement for access to health information through the Apple III]]

The Apple III introduced an advanced operating system called [[Apple SOS]], pronounced "apple sauce". Its ability to address resources by name allows the Apple III to be more scalable than the Apple II's addressing by physical location such as <code>PR#6</code> and <code>CATALOG, D1</code>. Apple SOS allows the full capacity of a storage device to be used as a single volume, such as the [[Apple ProFile]] [[hard disk drive]], and it supports a [[hierarchical file system]]. Some of the features and [[codebase|code]] base of Apple SOS were later adopted into the Apple II's [[Apple ProDOS|ProDOS]]<ref>{{cite book|title=Beneath Apple ProDOS|author1=Don Worth|author2=Pieter Lechner|publisher=Quality Software|year=1985|pages=2-4, 4-1, 6-12, E-3|isbn=0-912985-05-4}}</ref> and [[Apple GS/OS|GS/OS]] operating systems, as well as [[Apple Lisa|Lisa 7/7]] and [[Classic Mac OS|Mac OS]].{{Citation needed|date=December 2016}}

With a starting price of $4,340 (equivalent to $17,356 as of 2024) and a maximum price of $7,800 (equivalent to $31,194 as of 2024), the Apple III was more expensive than many of the [[CP/M]]-based business computers that were available at the time.<ref name="avuqmb" /> Few software applications other than VisiCalc are available for the computer;{{r|moore198209}} according to a presentation at [[KansasFest]] 2012, fewer than 50 Apple III-specific software packages were ever published, most shipping when the III Plus was released.<ref name="kansasfest2012">{{Cite AV media |url=https://www.youtube.com/watch?v=St08mKEG2EM#t=31m42s | archive-url=https://ghostarchive.org/varchive/youtube/20211122/St08mKEG2EM| archive-date=2021-11-22 | url-status=live|title=Apple III: A Closer Look |date=May 25, 2012 |last=Maginnis |first=Mike |via=YouTube |time=31:42}}{{cbignore}}</ref> However this number is proven to be wildly incorrect, given the manual 'RESOURCE GUIDE: Of Apple /// and Apple /// Plus Software and Hardware' published and released by Apple Computer, Inc. in May 1984 lists in excess of 500+ software packages produced by many and varied publishers. Given software publishers and specialised hardware manufacturers such as On-Three, Inc. produced products for the Apple III well in to the late 90s, in excess of 500 products can also be seen as way too conservative.

Because Apple did not view the Apple III as suitable for hobbyists, it did not provide much of the technical software information that accompanies the Apple II.<ref name="moore198209" /> Originally intended as a direct replacement to the Apple II, it was designed to be [[backward compatible]] with Apple II software. However, since Apple did not want to encourage continued development of the II platform, Apple II compatibility exists only in a special Apple II Mode which is limited in its capabilities to the [[emulator|emulation]] of a basic Apple II Plus configuration with {{val|48|ul=kB}} of RAM.

Special chips were intentionally added to prevent access from Apple II Mode to the III's advanced features such as its larger amount of memory.<ref name="byte198501" />

===Peripherals===
The Apple III has four expansion slots, a number that ''inCider'' in 1986 called "miserly".,<ref name="obrien198609">{{cite magazine |last=Obrien |first=Bill |date=September 1986 |title=And II For All |magazine=inCider |url=https://archive.org/stream/inCider_1986-09 |access-date=July 2, 2014| pages=[https://archive.org/stream/inCider_1986-09#page/n37/mode/2up 38], [https://archive.org/stream/inCider_1986-09#page/n91/mode/2up 94–95]}}</ref> also saying Apple II cards are compatible but risk violating government [[electromagnetic interference|RFI]] regulations, and require Apple III-specific [[device driver]]s; ''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<ref name="moore198209" /> but Apple III-specific products became available, such as one that made the computer compatible with the [[Apple IIe]].<ref name="obrien198609" /> Several new Apple-produced peripherals were developed for the Apple III. The original Apple III has a built-in [[real-time clock]], which is recognized by Apple SOS. The clock was later removed from the "revised" model, and was instead made available as an add-on.

Along with the built-in floppy drive, the Apple III can also handle up to three additional external Disk III floppy disk drives. The [[Disk III]] is only officially compatible with the Apple III. The Apple III Plus requires an adaptor from Apple to use the Disk III with its DB-25 disk port.<ref>{{cite web | url=http://support.apple.com/kb/TA31434 | title=Archived - Floppy Disk Drives: Apple III Plus External Drive Adapter | work=Apple | date=February 19, 2012 | access-date=November 23, 2013 | archive-date=December 2, 2013 | archive-url=https://web.archive.org/web/20131202235027/http://support.apple.com/kb/TA31434 | url-status=live }}</ref>

With the introduction of the revised Apple III a year after launch, Apple began offering the [[Apple ProFile|ProFile]] external hard disk system.<ref name = "bott" /> Priced at $3,499 for 5&nbsp;MB of storage, it also required a peripheral slot for its controller card.

===Backward compatibility===
The Apple III has the built-in hardware capability to run Apple II software. In order to do so, an emulation boot disk is required that functionally turns the machine into a standard 48-kilobyte [[Apple II Plus]], until it is powered off. The keyboard, internal floppy drive (and one external Disk III), display (color is provided through the 'B/W video' port) and speaker all act as Apple II peripherals. The [[paddle (game controller)|paddle]] and [[serial port]]s can also function in Apple II mode, however with some limitations and compatibility issues.

Apple engineers added specialized circuitry with the sole purpose of blocking access to its advanced features when running in Apple II emulation mode. This was done primarily to discourage further development and interest in the Apple II line, and to push the Apple III as its successor. For example, no more than {{nowrap|48 KB}} of RAM can be accessed, even if the machine has {{nowrap|128 KB}} of RAM or higher present. Many Apple II programs require a minimum of {{nowrap|64 KB}} of RAM, making them impossible to run on the Apple III. Similarly, access to lowercase support, 80 columns text, or its more advanced graphics and sound are blocked by this hardware circuitry, making it impossible for even skilled software programmers to bypass Apple's lockout. A third-party company, Titan Technologies, sold an expansion board called the III Plus II that allows Apple II mode to access more memory, a standard game port, and with a later released companion card, even emulate the Apple IIe.

Certain Apple II slot cards can be installed in the Apple III and used in native III-mode with custom written SOS device drivers, including Grappler Plus and Liron 3.5 Controller.

===Revisions===
[[File:Apple III+.jpg|thumb|Apple III Plus]]

After overheating issues were attributed to serious design flaws, a redesigned logic board was introduced in mid-December 1981{{sfn|Linzmayer|2004|pp=41–43}} – which included a lower power supply requirement, wider [[signal trace|circuit traces]] and better-designed chip sockets.<ref name="bott">{{cite web|url=http://applemuseum.bott.org/sections/computers/III.html|title=Apple III|website=Bott.org|access-date=August 2, 2009|archive-date=September 28, 2011|archive-url=https://web.archive.org/web/20110928005535/http://applemuseum.bott.org/sections/computers/III.html|url-status=live}}</ref> The $3,495 revised model also includes 256&nbsp;KB of RAM as the standard configuration.<ref name="bott" /> 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.<ref name="maceiie19840409" /><ref name="shea19840123">{{cite magazine | url=https://books.google.com/books?id=fC4EAAAAMBAJ&pg=PA17 | title=Apple releases overhauled III as the III Plus | magazine=[[InfoWorld]] |volume=6|issue=4|issn=0199-6649|oclc=923931674|publisher=IDG|location=United States| date=January 23, 1984 | access-date=February 9, 2015 | last=Shea | first=Tom | page=17}}</ref> It introduced the '''Apple III Plus''' in December 1983 at a price of US$2,995. This newer version includes a built-in clock, [[interlaced video|video interlacing]], standardized rear port connectors, 55-watt power supply, 256&nbsp;KB of RAM as standard, and a redesigned, Apple IIe-like keyboard.<ref name="bott" /><ref name="shea19840123" />

Owners of the Apple III could purchase individual III Plus upgrades, like the clock and interlacing feature,<ref name="shea19840123" /> 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 [[read-only memory|ROM]], and logo replacements. This upgrade had to be installed by an authorized service technician.

==Design flaws==
{{more citations needed section|date=September 2022}}
According to Wozniak, the Apple III "had 100 percent hardware failures".<ref name="byte198501" /> Former Apple executive Taylor Pohlman stated that:<ref name="bartimo19841210">{{cite magazine | url=https://books.google.com/books?id=si4EAAAAMBAJ&pg=PA41 | title=Q&A: Taylor Pohlman | magazine=[[InfoWorld]] |volume=6|issue=50|location=United States|publisher=IDG|issn=0199-6649|oclc=923931674| date=December 10, 1984 | access-date=January 5, 2015 | last1=Bartimo|first1=Jim | page=41}}</ref>

{{Blockquote|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 wrap|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.}}

Jobs insisted on the idea of having no fan or air vents, in order to make the computer run quietly. He 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]].<ref>{{cite web|first=Bob|last=Estes|date=May 15, 2009|website=On-Screen Scientist|url=http://onscreen-scientist.com/?tag=fan-control|title=First Cool, Now Quiet|access-date=August 2, 2009|archive-date=August 23, 2011|archive-url=https://web.archive.org/web/20110823180201/http://onscreen-scientist.com/?tag=fan-control|url-status=live}}</ref> To allow the computer to dissipate heat, the base of the Apple III was made of heavy cast aluminum, which supposedly acts as a [[heat sink]]. One 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, 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 was not enough room on the motherboard for all of the components unless narrow traces were used.

[[File:Apple III+ case.jpg|thumb|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 ///",<ref name="obrien198609" /> 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 [[Floppy disk|disk]] to come out of the slot "melted".<ref>{{Cite web|date=2007-07-14|title=Apple III and Apple IIe › Mac History|url=https://www.mac-history.net/computer-history/2007-07-14/apple-iii-and-apple-iie|access-date=2021-07-21|website=Mac History|language=en-US|archive-date=July 21, 2021|archive-url=https://web.archive.org/web/20210721182841/https://www.mac-history.net/computer-history/2007-07-14/apple-iii-and-apple-iie|url-status=live}}</ref> ''[[BYTE]]'' wrote, "the integrated circuits tended to [[chip creep|wander out of their sockets]]".<ref name="moore198209">{{cite magazine | url=https://archive.org/stream/byte-magazine-1982-09/1982_09_BYTE_07-09_Computers_and_the_Disabled#page/n93/mode/2up | title=The Apple III and Its New Profile | magazine=[[Byte (magazine)|BYTE]] |volume=7|number=9|publisher=UBM Technology Group|issn=0360-5280|oclc=637876171|location=United States| date=September 1982 | access-date=October 19, 2013 | author=Moore, Robin | page=92}}</ref> It has been rumored Apple advised customers to tilt the front of the Apple III six inches above the desk and then drop it to reseat the chips as a temporary solution.{{sfn|Linzmayer|2004|pp=41–43}} Other analyses blame a faulty automatic chip insertion process, not heat.<ref>{{cite web|title=What Really Killed the Apple III|url=http://www.applelogic.org/AIIIDesignBugs.html|website=AppleLogic|access-date=July 9, 2015|archive-date=September 14, 2022|archive-url=https://web.archive.org/web/20220914193313/http://www.applelogic.org/AIIIDesignBugs.html|url-status=live}}</ref>

Case designer [[Jerry Manock]] denied the design flaw charges, insisting 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.<ref name="youtube.com">{{cite AV media|date=Nov 13, 2007|url=https://www.youtube.com/watch?v=--7Br07QKMk| archive-url=https://ghostarchive.org/varchive/youtube/20211122/--7Br07QKMk| archive-date=2021-11-22 | url-status=live|first1=Robert|last1=Brunner|first2=Jerry|last2=Manock|publisher=Computer History Museum|title=Apple Industrial Designers Robert Brunner and Jerry Manock|id=Catalog number 102695056}}{{cbignore}}</ref> When chips were "stuffed" into the board and [[Wave soldering|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 [[drawing board|drafting board]], rather than using the costly [[Computer-aided design|CAD]]-[[Computer-aided manufacturing|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.<ref name="moore198209" /> 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 replace 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.{{sfn|Linzmayer|2004|pp=41–43}}

==BASIC==
{{More citations needed|section|date=March 2023}}
[[Microsoft]] and Apple each developed their own versions of BASIC for the Apple III. '''Apple III Microsoft BASIC''' was designed to run on the [[CP/M]] platform available for the Apple III. '''Apple Business BASIC''' shipped with the Apple III. Donn Denman ported Applesoft BASIC to SOS and reworked it to take advantage of the extended memory of the Apple III.

Both languages introduced a number of new or improved features over [[Applesoft BASIC]]. Both languages replaced Applesoft's single-precision [[floating-point]] variables using 5-[[byte]] storage with the somewhat-reduced-precision 4-byte variables, while also adding a larger numerical format. Apple III Microsoft BASIC provides double-precision floating-point variables, taking 8 bytes of storage,<ref>Apple III Microsoft BASIC Reference Manual, Microsoft Corporation, 1982</ref> while Apple Business BASIC offers an extra-long integer type, also taking 8 bytes for storage.<ref>Apple Business BASIC Reference Manual, Apple Computer, Inc., 1981</ref> Both languages also retain 2-byte integers, and maximum 255-character [[string (computer science)|strings]].

Other new features common to both languages include:
*Incorporation of disk-file commands within the language.
*Operators for MOD and for integer-division.
*An optional ELSE clause in IF...THEN statements.
*HEX$() function for [[hexadecimal]]-format output.
*INSTR function for finding a substring within a string.
*PRINT USING statement to control format of output. Apple Business BASIC had an option, in addition to directly specifying the format with a string expression, of giving the line number where an IMAGE statement gave the formatting expression, similar to a FORMAT statement in [[Fortran|FORTRAN]].

Some features work differently in each language:
{| class="wikitable"
! scope="col" width="150px" |
! scope="col" width="230px" | Apple III Microsoft BASIC
! scope="col" width="265px" | Apple Business BASIC
|-
| integer division operator
| \ (backslash)
| DIV
|-
| reading the keyboard without waiting
| INKEY$ function returns a one-character string representing the last key pressed, or the null string if no new key pressed since last reading
| KBD read-only "reserved variable" returns the ASCII code of the last key pressed; the manual fails to document what is returned if no new key pressed since last reading
|-
| reassigning a portion of a string variable
| MID$() assignment statement || SUB$() assignment statement
|-
| determining position of text output
| POS() function to read horizontal screen position, and LPOS() function to read horizontal position on printer
| HPOS and VPOS assignable "reserved variables" to read or set the horizontal or vertical position for text screen output
|-
| accepting hexadecimal-format values
| "&H"-formatted expressions
| TEN() function to give numerical value from string representing hexadecimal
|-
| result of ASC("")
(null string operand)
| causes an error
| returns the value −1
|}

===Microsoft BASIC additional features===
*{{mono|INPUT$()}} function to replace Applesoft's {{mono|GET}} command.
*{{mono|LINE}} {{mono|INPUT}} statement to input an entire line of text, regardless of punctuation, into a single string variable.
*{{mono|LPRINT}} and {{mono|LPRINT}} {{mono|USING}} statements to automatically direct output to paper.
*{{mono|LSET}} and {{mono|RSET}} statements to left- or right-justify a string expression within a given string variable's character length.
*{{mono|OCT$()}} function for output, and "&"- or "&O"-formatted expressions, for manipulating octal notation.
*{{mono|SPACE$()}} function for generating blank spaces outside of a {{mono|PRINT}} statement, and {{mono|STRING$()}} function to do likewise with any character.
*{{mono|WHILE}}...{{mono|WEND}} statements, for loop structures built on general [[Boolean data type|Boolean]] conditions without an index variable.
*[[bitwise operation|Bitwise]] Boolean (16-bit) operations ({{mono|AND}}, {{mono|OR}}, {{mono|NOT}}), with additional operators {{mono|XOR}}, {{mono|EQV}}, {{mono|IMP}}.
*Line number specification in the {{mono|RESTORE}} command.
*{{mono|RESUME}} options of {{mono|NEXT}} (to skip to the statement after that which caused the error) or a specified line number (which replaces the idea of exiting error-handling by {{mono|GOTO}}-line, thus avoiding Applesoft II's [[stack (abstract data type)|stack]] error problem).
*Multiple parameters in user-defined ({{mono|DEF FN}}) functions.
*A return to the old Applesoft One concept of having multiple {{mono|USR()}} functions at different addresses, by establishing ten different {{mono|USR}} functions, numbered {{mono|USR0}} to {{mono|USR9}}, with separate {{mono|DEF USRx}} statements to define the address of each. The argument passed to a {{mono|USRx}} function can be of any specific type, including string. The returned value can also be of any type, by default the same type as the argument passed.

There is no support for graphics provided within the language, nor for reading analog controls or buttons; nor is there a means of defining the active window of the text screen.

===Business BASIC additional features===
Apple Business BASIC eliminates all references to absolute memory addresses. Thus, the POKE command and PEEK() function were not included in the language, and new features replaced the CALL statement and USR() function. The functionality of certain features in Applesoft that had been achieved with various [[PEEK and POKE]] locations is now provided by:
* BUTTON() function to read game-controller buttons
* WINDOW statement to define the active window of the text screen by its coordinates
* KBD, HPOS, and VPOS system variables

External binary [[subroutines]] and functions are loaded into memory by a single INVOKE disk-command that loads separately-assembled code modules. A PERFORM statement is then used to call an INVOKEd procedure by name, with an argument-list. INVOKEd functions would be referenced in expressions by EXFN. (floating-point) or EXFN%. (integer), with the function name appended, plus the argument-list for the function.

Graphics are supported with an INVOKEd module, with features including displaying text within graphics in various fonts, within four different graphics modes available on the Apple III.

==Reception==

{{Cquote|It was unfortunate the way things worked out, because we probably put $100 million in advertising, promotion, and research and development into a product that was 3 percent of our revenues. In that same time frame, think what we could have done to improve the Apple II, or how much could have been done by Apple to give us products in IBM's market.|author=[[Steve Wozniak]], 1985{{r|byte198501}}|float=right |width=30% |quotealign=right }}

"The Apple III is unlikely to approach the success of the Apple II", ''[[InfoWorld]]'' said in January 1981. Citing the III's high price, manufacturing delays, limited disk storage, and small software library, the magazine asked "why buy a $5000 computer with an emulator when most of the programs you need run directly on a $2500 computer".<ref name="barry19810119">{{Cite magazine |last=Barry |first=Tim |date=1981-01-19 |title=Apple Grapples with Problems |url=https://books.google.com/books?id=kz4EAAAAMBAJ&lpg=PP5&pg=PP6#v=onepage&q&f=true |access-date=2025-04-12 |magazine=InfoWorld |pages=6, 10}}</ref>

Despite devoting the majority of its [[R&D]] to the Apple III and so ignoring the II that for a while dealers had difficulty in obtaining the latter,<ref name="mcmullen19840221">{{cite magazine | url=https://archive.org/details/PC-Mag-1984-02-21| title=Apple Charts The Course For IBM | magazine=[[PC Magazine]] |volume=3|number=3|publisher=Ziff Davis|oclc=805084898|issn=0888-8507| date=February 21, 1984 | access-date=October 24, 2013 |author1=McMullen, Barbara E.  |author2=John F. | page=122}}</ref> the III's technical problems made marketing the computer difficult. Ed Smith, who after designing the [[APF Imagination Machine]] worked as a distributor's representative, described the III as "a complete disaster". He recalled that he "was responsible for going to every dealership, setting up the Apple III in their showroom, and then explaining to them the functions of the Apple III, which in many cases didn't really work".<ref name="edwards20170222">{{Cite web |url=http://www.vintagecomputing.com/index.php/archives/1230/ed-smith-interview |title=VC&G Anthology Interview: Ed Smith, Black Video Game and Computer Pioneer |last=Edwards |first=Benj |date=February 22, 2017 |website=Vintage Computing and Games |access-date=May 19, 2017 |archive-date=May 19, 2017 |archive-url=https://web.archive.org/web/20170519210523/http://www.vintagecomputing.com/index.php/archives/1230/ed-smith-interview |url-status=live }}</ref>

===Sales===
''BYTE'' reported in 1982 that Apple had sold only 10,000 of the original Apple III, compared to 350,000 Apple IIs sold by the end of 1981.<ref name="libes198205">{{Cite magazine |last=Libes |first=Sol |date=May 1982 |title=Bytelines |url=https://archive.org/details/eu_BYTE-1982-05_OCR/page/n389/mode/1up?view=theater |magazine=BYTE |pages=388–396}}</ref> Pohlman reported that Apple was only selling 500 units a month by late 1981, mostly as replacements. The company was able to eventually raise monthly sales to 5,000, but the [[IBM Personal Computer|IBM PC]]'s successful launch had encouraged software companies to develop for it instead, prompting Apple to shift focus to the Lisa and Macintosh.<ref name="bartimo19841210" /> The PC almost ended sales of the Apple III, the most closely comparable Apple computer model.<ref name="pollack19830327">{{Cite news |last=Pollack |first=Andrew |url=https://www.nytimes.com/1983/03/27/business/big-ibm-has-done-it-again.html |title=Big I.B.M. Has Done It Again |date=1983-03-27 |work=The New York Times |access-date=2020-03-16 |page=Section 3, Page 1 |language=en-US |issn=0362-4331 |url-access=limited |archive-date=May 21, 2020 |archive-url=https://web.archive.org/web/20200521110634/https://www.nytimes.com/1983/03/27/business/big-ibm-has-done-it-again.html |url-status=live }}</ref> By early 1984, sales were primarily to existing III owners, Apple itself—its 4,500 employees were equipped with some 3,000-4,500 units—and some small businesses.<ref name="maceiie19840409">{{cite magazine | url=https://books.google.com/books?id=jC4EAAAAMBAJ&pg=PA54 | title=Apple IIe Sales Surge as IIc is Readied | magazine=[[InfoWorld]] | volume=6 | number=15 | publisher=IDG | oclc=421861736 | issn=0199-6649 | location=United States | date=April 9, 1984 | access-date=February 4, 2015 | author=Mace, Scott | pages=54–55 | archive-date=April 14, 2021 | archive-url=https://web.archive.org/web/20210414054643/https://books.google.com/books?id=jC4EAAAAMBAJ&pg=PA54 | url-status=live }}</ref><ref name="shea19840123" /> Apple finally discontinued the Apple III series on April 24, 1984, four months after introducing the III Plus, after selling only up to 75,000 units and replacing 14,000 defective units.<ref name="coventry20131006" />

Jobs said the company lost "incalculable amounts" of money on the Apple III.<ref name="coventry20131006">{{cite web | url=http://lowendmac.com/2013/apple-iii-chaos-apples-first-failure/ | title=Apple III Chaos: Apple's First Failure | publisher=Low End Mac | date=October 6, 2013 | access-date=July 1, 2014 | author=LEM Staff | archive-date=May 20, 2017 | archive-url=https://web.archive.org/web/20170520141747/http://lowendmac.com/2013/apple-iii-chaos-apples-first-failure/ | url-status=live }}</ref> Wozniak estimated that Apple had spent $100 million on the III instead of improving the II and better competing against IBM.{{r|byte198501}} Pohlman claimed that there was a "stigma" at Apple associated with having contributed to the computer. Most employees who worked on the III reportedly left Apple.<ref name="bartimo19841210" />

==Legacy==
The [[file system]] 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]] 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 [[FAT12|file system]] (again designed for floppy disks) was also flat and later versions (designed for hard disks) were hierarchical.{{citation needed|date=March 2023}}

===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.<ref>{{cite web|url=http://www.cedmagic.com/history/tron-apple3.html|title=1980: Apple III Business Computer|quote=The picture above is 07:31 into Side 1 of the CED movie TRON, where Kevin Flynn (Jeff Bridges) is using an Apple III at home...|access-date=July 7, 2015|archive-date=June 27, 2015|archive-url=https://web.archive.org/web/20150627100705/http://www.cedmagic.com/history/tron-apple3.html|url-status=live}}</ref>

{{Timeline of Apple II Family|headerextension==}}

==References==
{{Reflist|30em}}

;Sources
* {{cite book|last=Linzmayer|first=Owen W.|year=2004|chapter=Apple III Fiasco |pages=41–44 |title=Apple Confidential 2.0: The Definitive History of the World's Most Colorful Company|publisher=No Starch Press |oclc=921280642 |isbn=9781593270100 |chapter-url=https://books.google.com/books?id=mXnw5tM8QRwC&pg=PA41}}

==External links==
{{commons category|Apple III}}
* [http://www.vectronicsappleworld.com/archives/appleii/0002.php The Ill-Fated Apple III]
* [http://www.1000bit.it/scheda.asp?id=16 Many manuals and diagrams]
* [http://www.blackcatsystems.com/software/sara.html Sara – Apple /// emulator]
* [http://lowendmac.com/2015/ill-fated-apple-iii/ The Ill-Fated Apple III] Low End Mac
* [http://lowendmac.com/2015/apple-iii-chaos-apples-first-failure/ Apple III Chaos: Apple's First Failure] Low End Mac

{{Apple hardware before 1998}}
{{Apple hardware}}
{{Authority control}}

[[Category:Apple II family]]
[[Category:Computer-related introductions in 1980]]
[[Category:Products and services discontinued in 1984]]
[[Category:Discontinued Apple Inc. products]]
[[Category:8-bit computers]]