Apple II Plus
Encyclopedia
The Apple II Plus was the second model of the Apple II series
of personal computer
s produced by Apple Computer, Inc. It was sold new from June 1979 to December 1982.
microprocessor could support a maximum of 64 KB of address space
, and a machine with 48KB RAM reached this limit because of the additional 12 KB of read-only memory and 4 KB of I/O addresses. For this reason, the extra RAM in the language card was bank-switched
over the machine's built-in ROM, allowing code loaded into the additional memory to be used as if it actually were ROM. Users could thus load Integer BASIC into the language card from disk and switch between the Integer
and Applesoft
dialects of BASIC with DOS 3.3
's INT and FP commands just as if they had the BASIC ROM expansion card. The Language Card was also required to use LOGO, Apple Pascal
, and FORTRAN 77
. Apple Pascal and FORTRAN ran under a non-DOS operating system based on UCSD P-System, which had its own disk format and included a "virtual machine
" that allowed it to run on many different types of hardware.
The Apple II Plus included the Applesoft BASIC
programming language in ROM. This Microsoft
-authored dialect of BASIC, which was previously available as an upgrade, supported floating-point arithmetic (though it ran at a noticeably slower speed than Steve Wozniak's Integer BASIC) and became the standard BASIC dialect on the Apple.
Like the Apple II
, the Apple II Plus had no lowercase functionality. All letters from the keyboard were upper-case, there was no caps lock
key, and there were no lowercase letters in the text-mode font
stored in the computer's ROM
. To display lowercase letters, some applications would run in the slower hi-res graphics mode and use a custom font, rather than running in the fast text mode using the font in ROM. Other programs, primarily those where both capitalization and text movement were important, such as word processor
s, used inverse text mode to represent text that would be lowercase when printed. Alternatively, users could install a custom ROM chip that contained lowercase letters in the font, or purchase one of several third-party 80-column cards that enabled a text mode that could display 80-column, upper- and lower-case text. The "Videx
Videoterm" card and its many clones were especially popular. For lowercase input, since it was not possible to detect whether the keyboard's Shift keys were in use, a modification called the "one-wire shift key mod" connected the Shift key to one of the pins on the motherboard's paddle
connector. Compatible applications, including nearly all word processor
s, could then detect whether the shift key was being pressed. This modification, however, involved adding wires inside the Apple II, and was therefore only popular among hobbyists. For this reason, most applications that could support lower-case letters could also use the ESC key as a substitute lowercase toggle if the "shift key mod" was not installed. The II Plus had a plastic case with brass mesh running along the inside of the case. This mesh protected the computer from harmful radio frequency energy
. Small grids of plastic pins, and sometimes Velcro
, was used to hold the case's top onto the computer.
Furthermore, the Apple II Plus, like its predecessor the Apple II, had a repeat key built into its keyboard. The key was labeled "REPT" and was located just to the left of the Enter key. The II Plus was the last Apple Computer to have this key, as later Apple computers would incorporate the ability to hold down a key for a period of time to repeat the key.
and the Far East
in 1978, with the Apple II Europlus (Europe) and the Apple II J-Plus (Japan). In these models, Apple made the necessary hardware, software and firmware
changes in order to comply to standards outside of the US. The power supply
was modified to accept the local voltage, and in the European model the video output signal was changed from color NTSC
to monochrome PAL
by changing some jumper
s on the motherboard and using a slightly different frequency crystal oscillator
— an extra video card (which only worked in slot 7) was needed for color PAL
graphics, since the simple tricks Wozniak had used to generate a pseudo-NTSC signal with minimal hardware did not carry over to the more complex PAL system. In the Japanese version of the international Apple, the character ROM and the keyboard layout were changed to allow for Katakana
writing (full Kanji
support was clearly beyond the capabilities of the machine), but in most other countries the international Apple was sold with an unmodified American keyboard; thus the German model still lacked the umlaut
s, for example, and had a QWERTY
layout instead of the standard German QWERTZ
. For the most part, the Apple II Europlus and J-Plus were identical to the Apple II Plus and software compatibility was near 100%. Production of the Europlus ended in 1983.
-listed because the top could be opened; the B&H model was the same as the consumer version sold by Apple except that it came in a black case, which could not be as easily opened, and a special A/V package allowing it to be sold as audio/visual equipment. Bell & Howell packaged the unit with optional "back packs" that offered various inputs and outputs for A/V equipment to easily interface with the II Plus. This was the only black computer Apple would manufacture until the Macintosh TV
in 1993.
-approved version of the Apple II Plus called the Microfix was developed in 1980 by the Georgia Tech Research Institute
for U.S. Army FORSCOM. Fielded in 1982, the Microfix system was the first tactical system using video disk (Laserdisc
) map technology providing zoom and scroll over map imagery coupled with a point database of intelligence data such as order of battle
, airfields, roadways, and bridges.
See also
External links
Apple II series
The Apple II series is a set of 8-bit home computers, one of the first highly successful mass-produced microcomputer products, designed primarily by Steve Wozniak, manufactured by Apple Computer and introduced in 1977 with the original Apple II...
of personal computer
Personal computer
A personal computer is any general-purpose computer whose size, capabilities, and original sales price make it useful for individuals, and which is intended to be operated directly by an end-user with no intervening computer operator...
s produced by Apple Computer, Inc. It was sold new from June 1979 to December 1982.
Features
The Apple II Plus had a total of 48 KB of RAM, expandable to 64 KB by means of the Language Card, an expansion card that could be installed in the computer's slot 0. The Apple's 6502MOS Technology 6502
The MOS Technology 6502 is an 8-bit microprocessor that was designed by Chuck Peddle and Bill Mensch for MOS Technology in 1975. When it was introduced, it was the least expensive full-featured microprocessor on the market by a considerable margin, costing less than one-sixth the price of...
microprocessor could support a maximum of 64 KB of address space
Address space
In computing, an address space defines a range of discrete addresses, each of which may correspond to a network host, peripheral device, disk sector, a memory cell or other logical or physical entity.- Overview :...
, and a machine with 48KB RAM reached this limit because of the additional 12 KB of read-only memory and 4 KB of I/O addresses. For this reason, the extra RAM in the language card was bank-switched
Bank switching
Bank switching is a technique to increase the amount of usable memory beyond the amount directly addressable by the processor. It can be used to configure a system differently at different times; for example, a ROM required to start a system from diskette could be switched out when no longer...
over the machine's built-in ROM, allowing code loaded into the additional memory to be used as if it actually were ROM. Users could thus load Integer BASIC into the language card from disk and switch between the Integer
Integer BASIC
Integer BASIC, written by Steve Wozniak, was the BASIC interpreter of the Apple I and original Apple II computers. Originally available on cassette, then included in ROM on the original Apple II computer at release in 1977, it was the first version of BASIC used by many early home computer owners...
and Applesoft
Applesoft BASIC
Applesoft BASIC was a dialect of Microsoft BASIC supplied with the Apple II series of computers. It superseded Integer BASIC and was the BASIC in ROM in all Apple II series computers after the original Apple II model. It was also referred to as FP because of the command used to invoke it instead...
dialects of BASIC with DOS 3.3
Apple DOS
Apple DOS refers to operating systems for the Apple II series of microcomputers from late 1978 through early 1983. Apple DOS had three major releases: DOS 3.1, DOS 3.2, and DOS 3.3; each one of these three releases was followed by a second, minor "bug-fix" release, but only in the case of Apple DOS...
's INT and FP commands just as if they had the BASIC ROM expansion card. The Language Card was also required to use LOGO, Apple Pascal
Apple Pascal
Apple Pascal was a language and operating system based on the UCSD Pascal system.Apple Pascal refers to an operating system for the Apple II family of computers released in August 1979 between the Apple DOS 3.2 and 3.3 versions. The system was included as part of a software/hardware package adding...
, and FORTRAN 77
Fortran
Fortran is a general-purpose, procedural, imperative programming language that is especially suited to numeric computation and scientific computing...
. Apple Pascal and FORTRAN ran under a non-DOS operating system based on UCSD P-System, which had its own disk format and included a "virtual machine
Virtual machine
A virtual machine is a "completely isolated guest operating system installation within a normal host operating system". Modern virtual machines are implemented with either software emulation or hardware virtualization or both together.-VM Definitions:A virtual machine is a software...
" that allowed it to run on many different types of hardware.
The Apple II Plus included the Applesoft BASIC
Applesoft BASIC
Applesoft BASIC was a dialect of Microsoft BASIC supplied with the Apple II series of computers. It superseded Integer BASIC and was the BASIC in ROM in all Apple II series computers after the original Apple II model. It was also referred to as FP because of the command used to invoke it instead...
programming language in ROM. This Microsoft
Microsoft
Microsoft Corporation is an American public multinational corporation headquartered in Redmond, Washington, USA that develops, manufactures, licenses, and supports a wide range of products and services predominantly related to computing through its various product divisions...
-authored dialect of BASIC, which was previously available as an upgrade, supported floating-point arithmetic (though it ran at a noticeably slower speed than Steve Wozniak's Integer BASIC) and became the standard BASIC dialect on the Apple.
Like the Apple II
Apple II
The Apple II is an 8-bit home computer, one of the first highly successful mass-produced microcomputer products, designed primarily by Steve Wozniak, manufactured by Apple Computer and introduced in 1977...
, the Apple II Plus had no lowercase functionality. All letters from the keyboard were upper-case, there was no caps lock
Caps lock
Caps lock is a key on many computer keyboards. Pressing it sets an input mode in which typed letters are uppercase by default. The keyboard remains in caps lock mode until the key is pressed again...
key, and there were no lowercase letters in the text-mode font
Font
In typography, a font is traditionally defined as a quantity of sorts composing a complete character set of a single size and style of a particular typeface...
stored in the computer's ROM
Read-only memory
Read-only memory is a class of storage medium used in computers and other electronic devices. Data stored in ROM cannot be modified, or can be modified only slowly or with difficulty, so it is mainly used to distribute firmware .In its strictest sense, ROM refers only...
. To display lowercase letters, some applications would run in the slower hi-res graphics mode and use a custom font, rather than running in the fast text mode using the font in ROM. Other programs, primarily those where both capitalization and text movement were important, such as word processor
Word processor
A word processor is a computer application used for the production of any sort of printable material....
s, used inverse text mode to represent text that would be lowercase when printed. Alternatively, users could install a custom ROM chip that contained lowercase letters in the font, or purchase one of several third-party 80-column cards that enabled a text mode that could display 80-column, upper- and lower-case text. The "Videx
Videx
Videx is a manufacturer of access control products and data collection terminals. Better known in the 1980s as manufacturer of Videx VideoTerm and Videx UltraTerm add-on expansion card for Apple II computers...
Videoterm" card and its many clones were especially popular. For lowercase input, since it was not possible to detect whether the keyboard's Shift keys were in use, a modification called the "one-wire shift key mod" connected the Shift key to one of the pins on the motherboard's paddle
Paddle (game controller)
A paddle is a game controller with a round wheel and one or more fire buttons, where the wheel is typically used to control movement of the player object along one axis of the video screen...
connector. Compatible applications, including nearly all word processor
Word processor
A word processor is a computer application used for the production of any sort of printable material....
s, could then detect whether the shift key was being pressed. This modification, however, involved adding wires inside the Apple II, and was therefore only popular among hobbyists. For this reason, most applications that could support lower-case letters could also use the ESC key as a substitute lowercase toggle if the "shift key mod" was not installed. The II Plus had a plastic case with brass mesh running along the inside of the case. This mesh protected the computer from harmful radio frequency energy
Electromagnetic interference
Electromagnetic interference is disturbance that affects an electrical circuit due to either electromagnetic induction or electromagnetic radiation emitted from an external source. The disturbance may interrupt, obstruct, or otherwise degrade or limit the effective performance of the circuit...
. Small grids of plastic pins, and sometimes Velcro
Velcro
Velcro is the brand name of the first commercially marketed fabric hook-and-loop fastener, invented in 1948 by the Swiss electrical engineer George de Mestral...
, was used to hold the case's top onto the computer.
Furthermore, the Apple II Plus, like its predecessor the Apple II, had a repeat key built into its keyboard. The key was labeled "REPT" and was located just to the left of the Enter key. The II Plus was the last Apple Computer to have this key, as later Apple computers would incorporate the ability to hold down a key for a period of time to repeat the key.
Apple II Europlus and J-Plus
After the success of the first Apple II in the United States, Apple expanded its market to include EuropeEurope
Europe is, by convention, one of the world's seven continents. Comprising the westernmost peninsula of Eurasia, Europe is generally 'divided' from Asia to its east by the watershed divides of the Ural and Caucasus Mountains, the Ural River, the Caspian and Black Seas, and the waterways connecting...
and the Far East
Far East
The Far East is an English term mostly describing East Asia and Southeast Asia, with South Asia sometimes also included for economic and cultural reasons.The term came into use in European geopolitical discourse in the 19th century,...
in 1978, with the Apple II Europlus (Europe) and the Apple II J-Plus (Japan). In these models, Apple made the necessary hardware, software and firmware
Firmware
In electronic systems and computing, firmware is a term often used to denote the fixed, usually rather small, programs and/or data structures that internally control various electronic devices...
changes in order to comply to standards outside of the US. The power supply
Power supply
A power supply is a device that supplies electrical energy to one or more electric loads. The term is most commonly applied to devices that convert one form of electrical energy to another, though it may also refer to devices that convert another form of energy to electrical energy...
was modified to accept the local voltage, and in the European model the video output signal was changed from color NTSC
NTSC
NTSC, named for the National Television System Committee, is the analog television system that is used in most of North America, most of South America , Burma, South Korea, Taiwan, Japan, the Philippines, and some Pacific island nations and territories .Most countries using the NTSC standard, as...
to monochrome PAL
PAL
PAL, short for Phase Alternating Line, is an analogue television colour encoding system used in broadcast television systems in many countries. Other common analogue television systems are NTSC and SECAM. This page primarily discusses the PAL colour encoding system...
by changing some jumper
Jumper (computing)
In electronics and particularly computing, a jumper is a short length of conductor used to close a break in or bypass part of an electrical circuit...
s on the motherboard and using a slightly different frequency crystal oscillator
Crystal oscillator
A crystal oscillator is an electronic oscillator circuit that uses the mechanical resonance of a vibrating crystal of piezoelectric material to create an electrical signal with a very precise frequency...
— an extra video card (which only worked in slot 7) was needed for color PAL
PAL
PAL, short for Phase Alternating Line, is an analogue television colour encoding system used in broadcast television systems in many countries. Other common analogue television systems are NTSC and SECAM. This page primarily discusses the PAL colour encoding system...
graphics, since the simple tricks Wozniak had used to generate a pseudo-NTSC signal with minimal hardware did not carry over to the more complex PAL system. In the Japanese version of the international Apple, the character ROM and the keyboard layout were changed to allow for Katakana
Katakana
is a Japanese syllabary, one component of the Japanese writing system along with hiragana, kanji, and in some cases the Latin alphabet . The word katakana means "fragmentary kana", as the katakana scripts are derived from components of more complex kanji. Each kana represents one mora...
writing (full Kanji
Kanji
Kanji are the adopted logographic Chinese characters hanzi that are used in the modern Japanese writing system along with hiragana , katakana , Indo Arabic numerals, and the occasional use of the Latin alphabet...
support was clearly beyond the capabilities of the machine), but in most other countries the international Apple was sold with an unmodified American keyboard; thus the German model still lacked the umlaut
Umlaut (diacritic)
The diaeresis and the umlaut are diacritics that consist of two dots placed over a letter, most commonly a vowel. When that letter is an i or a j, the diacritic replaces the tittle: ï....
s, for example, and had a QWERTY
QWERTY
QWERTY is the most common modern-day keyboard layout. The name comes from the first six letters appearing in the topleft letter row of the keyboard, read left to right: Q-W-E-R-T-Y. The QWERTY design is based on a layout created for the Sholes and Glidden typewriter and sold to Remington in the...
layout instead of the standard German QWERTZ
QWERTZ
thumb|175px|A computer QWERTZ keyboardThe QWERTZ or QWERTZU keyboard is a widely used computer and typewriter keyboard layout that is mostly used in Central Europe...
. For the most part, the Apple II Europlus and J-Plus were identical to the Apple II Plus and software compatibility was near 100%. Production of the Europlus ended in 1983.
Bell & Howell
The Apple II Plus was also sold by Bell & Howell specifically to educational markets under special license from Apple. The normal consumer Apple II Plus was not ULUnderwriters Laboratories
Underwriters Laboratories Inc. is an independent product safety certification organization. Established in 1894, the company has its headquarters in Northbrook, Illinois. UL develops standards and test procedures for products, materials, components, assemblies, tools and equipment, chiefly dealing...
-listed because the top could be opened; the B&H model was the same as the consumer version sold by Apple except that it came in a black case, which could not be as easily opened, and a special A/V package allowing it to be sold as audio/visual equipment. Bell & Howell packaged the unit with optional "back packs" that offered various inputs and outputs for A/V equipment to easily interface with the II Plus. This was the only black computer Apple would manufacture until the Macintosh TV
Macintosh TV
The Macintosh TV was Apple's first attempt at computer-television integration. It shared the external appearance of the Macintosh LC 500 series, but in black. The Macintosh TV was essentially a Performa 520 that could switch its built-in 14" Sony Trinitron CRT from being a computer display to a...
in 1993.
Military applications
A TEMPESTTEMPEST
TEMPEST is a codename referring to investigations and studies of compromising emission . Compromising emanations are defined as unintentional intelligence-bearing signals which, if intercepted and analyzed, may disclose the information transmitted, received, handled, or otherwise processed by any...
-approved version of the Apple II Plus called the Microfix was developed in 1980 by the Georgia Tech Research Institute
Georgia Tech Research Institute
The Georgia Tech Research Institute is the nonprofit applied research arm of the Georgia Institute of Technology in Atlanta, Georgia, United States...
for U.S. Army FORSCOM. Fielded in 1982, the Microfix system was the first tactical system using video disk (Laserdisc
Laserdisc
LaserDisc was a home video format and the first commercial optical disc storage medium. Initially licensed, sold, and marketed as MCA DiscoVision in North America in 1978, the technology was previously referred to interally as Optical Videodisc System, Reflective Optical Videodisc, Laser Optical...
) map technology providing zoom and scroll over map imagery coupled with a point database of intelligence data such as order of battle
Order of battle
In modern use, the order of battle is the identification, command structure, strength, and disposition of personnel, equipment, and units of an armed force participating in field operations. Various abbreviations are in use, including OOB, O/B, or OB, while ORBAT remains the most common in the...
, airfields, roadways, and bridges.
See also
- Apple II seriesApple II seriesThe Apple II series is a set of 8-bit home computers, one of the first highly successful mass-produced microcomputer products, designed primarily by Steve Wozniak, manufactured by Apple Computer and introduced in 1977 with the original Apple II...
- Apple IIIApple IIIThe Apple III 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...
- Apple IIeApple IIeThe Apple IIe is the third model in the Apple II series of personal computers produced by Apple Computer. The e in the name stands for enhanced, referring to the fact that several popular features were now built-in that were only available as upgrades and add-ons in earlier models...
- Apple IIcApple IIcThe Apple IIc, the fourth model in the Apple II series of personal computers, was Apple Computer’s first endeavor to produce a portable computer. The end result was a notebook-sized version of the Apple II that could be transported from place to place...
- Apple IIc PlusApple IIc PlusThe Apple IIc Plus is the sixth and final model in the Apple II line of personal computers, produced by Apple Computer. The "Plus" in the name was a reference to the additional features it offered over the original portable Apple IIc, such as greater storage capacity , increased processing speed,...
- Apple IIGSApple IIGSThe Apple , the fifth and most powerful model in the Apple II series of personal computers produced by Apple Computer. The "GS" in the name stands for Graphics and Sound, referring to its enhanced graphics and sound capabilities, both of which greatly surpassed previous models of the line...
- List of Apple II games
- Apple II peripheral cardsApple II peripheral cardsThe Apple II line of computers supported a number of Apple II peripheral cards, expansion cards which plugged into slots on the motherboard, and added to and extended the functionality of the base system....
- Publications/Periodicals devoted to the Apple II
- ReactiveMicro.com—An Apple II hardware production company (cloned items)
External links
Apple II series
The Apple II series is a set of 8-bit home computers, one of the first highly successful mass-produced microcomputer products, designed primarily by Steve Wozniak, manufactured by Apple Computer and introduced in 1977 with the original Apple II...
Apple III
The Apple III 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...
Apple IIe
The Apple IIe is the third model in the Apple II series of personal computers produced by Apple Computer. The e in the name stands for enhanced, referring to the fact that several popular features were now built-in that were only available as upgrades and add-ons in earlier models...
Apple IIc
The Apple IIc, the fourth model in the Apple II series of personal computers, was Apple Computer’s first endeavor to produce a portable computer. The end result was a notebook-sized version of the Apple II that could be transported from place to place...
Apple IIc Plus
The Apple IIc Plus is the sixth and final model in the Apple II line of personal computers, produced by Apple Computer. The "Plus" in the name was a reference to the additional features it offered over the original portable Apple IIc, such as greater storage capacity , increased processing speed,...
Apple IIGS
The Apple , the fifth and most powerful model in the Apple II series of personal computers produced by Apple Computer. The "GS" in the name stands for Graphics and Sound, referring to its enhanced graphics and sound capabilities, both of which greatly surpassed previous models of the line...
Apple II peripheral cards
The Apple II line of computers supported a number of Apple II peripheral cards, expansion cards which plugged into slots on the motherboard, and added to and extended the functionality of the base system....
- Vintage Computers - Apple II Plus
- ReactiveMicro.com — The last remaining Apple II hardware production company (cloned items)