Apple II

The Apple II was originally running only the built-in BASIC interpreter contained in ROM. Apple DOS was added to support the diskette drive; the last version was "Apple DOS 3.3". Apple DOS was superseded by ProDOS to support a hierarchical filesystem and larger storage devices. Using a diskette or hard-disk, the Apple II could also load the UCSD Pascal operating system. UCSD binaries are compatible with a large number of other computers, including the IBM-PC. Using a Z80 interface the Apple II could run the popular Wordstar and dBase software under the CP/M operating system.

The approach taken in the Disk II controller was typical of Wozniak's design sensibility. The Apple II was full of clever engineering tricks to save hardware and reduce costs. For example, taking advantage of the way that 6502 instructions only access memory every other clock cycle, the video generation circuitry's memory access on the otherwise unused cycles avoided memory contention issues and also eliminated the need for a separate refresh circuit for the DRAM chips.

The text and graphics screens had a somewhat outdated arrangement (the scanlines were not stored in sequential areas of memory) which was reputedly due to Woz's realization that doing it that way would save a chip; it was less expensive to have software calculate or look up the address of the required scanline than to include the extra hardware. Similarly, in the high-resolution graphics mode, color was determined by pixel position and could thus be implemented in software, saving Woz the chips needed to convert bit patterns to colors.

The epitome of the Apple II design philosophy was the Apple II sound circuitry. Rather than having a dedicated sound-synthesis chip, the Apple II had a toggle circuit that could only emit a click through a built-in speaker; all other sounds (including two, three and, eventually, four-voice music and playback of audio samples and speech synthesis) were generated entirely by clever software that clicked the speaker at just the right times. Not for nearly a decade would an Apple II be released with a dedicated sound chip. Similar techniques were used for cassette storage: the cassette output worked the same as the speaker, and the input was a simple zero-crossing detector that served as a relatively crude (1-bit) audio digitizer. Routines in the ROM were used to encode and decode data in frequency shift keying for the cassette.

Wozniak的开放式设计与Apple II的多个扩充槽使它得以借由大量的第三方装置以扩充其功能。Apple II peripheral cards such as Serial controllers, improved display controllers, memory boards, hard disks, and networking components were available for this system in its day. There were emulator cards, such as the Z80 card that permitted the Apple to switch to the Z80 processor and run a multitude of programs developed under the CP/M operating system, including the dBase II database and the WordStar word processor. (At one point in the mid-1980's, more than half the machines running CP/M were Apple II's with Z80 cards.)There was also a third-party 6809 card that would allow OS-9 Level One to be run. The Mockingboard sound card greatly improved the audio capabilities of the Apple, with simple music synthesis and text-to-speech functions. Eventually, Apple II accelerator cards were created to double or quadruple the computer's speed.

Apple II Plus共有48KB的内存，并可借由能安装在扩充槽0的16 KB内存扩充”语言卡”将内存扩充至64KB。苹果公司采用的6502微处理器支持最大64KB内存，而一台有48KB内存的机器刚好达到这个上限，因为扩充的16KB ROM与I/O地址。因此，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 the UCSD Pascal and FORTRAN 77 compilers, which were released by Apple at about the same time. These ran under a non-DOS operating system called the 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 UCSD P-system had a curious approach to memory management, which became even more curious on the Apple III.

1983年，Apple IIe的发表接续了Apple II+。它是一款较便宜但功能更强大的机器，采用了较新的芯片以减低成本并添加新功能。例如可显示大小写字母及有64KB内存。IIe的内存被设置成如同48KB的Apple II Plus加装语言卡。这款机型没有插槽0，但有一个提供所有使际使用的附加插槽3－在Apple II+里通常给80例卡使用。The auxiliary slot could accept a 1 KB memory card to enable the 80-column display. This card contained only RAM; the hardware and firmware for the 80-column display was built into the Apple IIe, remaining fairly compatible with the older Videx-style cards, even though the low-level details were very different. An "extended 80-column card" with more memory expanded the machine's RAM to 128 KB. As with the language card, the memory in the 80-column card was bank-switched over the machine's main RAM; this made the memory better suited to data storage than to running software, and in fact the ProDOS operating system, which was introduced with the Apple IIe, would automatically configure this memory as a RAM disk upon booting. Third-party aux-slot memory cards later allowed expansion up to 1 MiB. The 1K 80-column card also enabled one new graphics mode, Double Lo-Res (80×48 pixels); the extended 80-column card enabled two, Double Lo-Res and Double Hi-Res (560×192 pixels). Both modes doubled the horizontal resolution in comparison to the standard Lo-Res (40×48) and Hi-Res (280×192) Modes; in the case of Double Hi-Res, the number of available colors was increased as well, from 6 to 15. Apple IIe's from the very first production run cannot use Double Hi-Res. Neither of these modes was directly supported by the built-in BASIC, however, so the user had to resort to the use of lots of POKE and CALL commands, or assembly language programming, or one of a number of software Toolkits to exploit these modes.

Introduced with the IIe was the DuoDisk, essentially two Disk II 5¼" drives in a single enclosure designed to stack between the computer and the monitor, and a new controller card to run it. This controller was (by design) functionally identical to the original Disk II controller but used a different connector, allowing a single cable to control both drives in the DuoDisk. The DuoDisk was plagued by reliability problems, however, and did not catch on as well as the IIe itself.

The IIe was the most popular Apple II ever built and was widely considered the "workhorse" of the line. It also has the distinction of being the longest-lived Apple computer of all time -- it was manufactured and sold with only minor changes for nearly eleven years. In that time, following the original, two important variations came to pass known as the Enhanced IIe (four new replacement chips to give it the same features as the later model Apple IIc, including an upgraded processor called the 65C02) and Platinum IIe (a modernized new look for the case color to match other Apple products of the era, along with the addition of a built-in numeric keypad). An Enhanced IIe with 128 KB of RAM can be considered the minimum requirement for running most Apple II software released after about 1988.

苹果电脑公司在1984年4月推出Apple IIc并以”便携式Apple II”的名义宣传它，因为它可以轻易地搬运。然而，它没有电源及内建显示器。The IIc even sported a carrying handle that folded down to prop the machine up into a typing position. It was the first of three Apple II models to be made in the Snow White design language, and the only one that was actually white. (The other Snow White computers from the Apple II series, the IIGS and the IIc Plus, were actually light gray, sometimes called "platinum" by Apple.)

The Apple IIc was the first Apple II to use the updated 65C02 processor, and featured a built-in 5.25" floppy drive and 128 KB RAM, with a built-in disk controller that could control external drives, composite video (NTSC or PAL), serial interfaces for modem and printer, and a joystick/mouse port. Unlike previous Apple II models, the IIc had no internal expansion slots at all, this being the means by which its compact size was attained. Third parties did eventually figure out how to wedge up to 1 MiB of additional memory and a real-time clock into the machine, and a later revision of the motherboard provided an expansion slot that could accept an Apple memory card bearing up to 1 MiB of RAM. The disk port, originally intended for a second 5¼" floppy drive, eventually was able to interface to 3½" disk drives and (via third parties) even hard disks.

To play up the portability, two different monochrome LCD displays were sold for use with the IIc's video expansion port, although both were short-lived due to high cost and poor legibility. (A IIc with the smaller of these displays appeared briefly in the film 2010.) The IIc had an external power supply that converted AC power to 12V DC, allowing third parties to offer battery packs and automobile power adapters that connected in place of the supplied AC adapter.

The Apple IIc (in its American version) was the first microcomputer to include support for the Dvorak Simplified Keyboard, which was activated using a switch above the keyboard. This feature was also later found in late-model American Apple IIe computers (though the switch was inside the computer) and in the Apple IIGS (accessible via the built-in control panel).

Apple II产品线的下一个成员是在1986年推出的Apple IIGS。 A radical departure from the existing Apple II line, the IIGS featured a true 16-bit microprocessor, the 65C816, operating at 2.8 MHz with 24-bit addressing, allowing expansion up to 8 MiB of RAM without the bank-switching hassles of the earlier machines (RAM cards with more than 4 MiB were never directly supported by Apple ^[5]). It introduced two completely new graphic modes sporting higher resolutions and a palette of 4,096 colors; however, only 4 (at 640×200 resolution) or 16 (at 320×200 resolution) colors could be used on a single line at a time, although a technique known as dithering was often employed in software to increase the number of perceived colors. ^[6]

In a departure from earlier Apple II graphics modes, the new modes laid out the scanlines sequentially in memory. However, programmers in search of a graphics challenge could always turn to 3200-color mode, which involved precisely swapping in a different 16-color palette for each of the screen's 200 scanlines as the monitor's electron beam traced the screen line by line. This exotic technique did not leave many CPU cycles available for other processing, so this "mode" was best suited to displaying static images.

The Apple IIGS stood out from any previous (or future) Apple II models, evolving and advancing the platform into the next generation of computing while still maintaining near-complete backward compatibility. The secret of the Apple IIGS's compatibility was a single chip called the Mega II, which contained the functional equivalent of an entire Apple IIe computer (sans processor), which, combined with the flawless 65C02 emulation mode of the 65C816 processor, provided full support for legacy software.

The computer also included a 32-voice Ensoniq wavetable music synthesizer ^[7] with 64 KB dedicated RAM, 256 KB of standard RAM, built-in peripheral ports (switchable between IIe-style card slots and IIc-style onboard controllers for disk drives, mouse, RGB video, and serial devices), built-in AppleTalk networking, and a ROM toolbox that supported a graphical user interface derived from the Macintosh toolbox. The computer could run existing 8-bit Apple II software (including software written for the very first Apple II in Integer BASIC), but also supported 16-bit software running under a new OS first called ProDOS 16 and later called GS/OS ^[6]. The new OS eventually included a Finder that could be used for managing disks and files and opening documents and applications, along with desk accessories -- just like the Macintosh. The 16-bit operating system would automatically switch to the text display and downshift to 8-bit mode to run legacy software, while offering a consistent, Macintosh-like graphical interface for native 16-bit applications. Eventually the IIGS gained the ability to read and write Macintosh disks and, through third-party software, even multitasking (both cooperative and preemptive, the latter in the form of a Unix-type shell), outline TrueType font support, and in one case, even real-time 3D gaming using texture mapping.

The final Apple II model was the Apple IIc Plus introduced in 1988. It was the same size and shape as the IIc that came before it, but the 5¼" floppy drive had been replaced with a 3½" drive, the power supply was moved inside (gone was the IIc's "brick on a leash" power supply), and the processor was a fast 4 MHz 65C02 processor that actually ran 8-bit Apple II software faster than the IIGS. (Third-party accelerators for other models could, however, go as fast as 10 MHz, and IIGS accelerators would eventually reach 16 MHz.) The IIc Plus's accelerator was derived from a design licensed from Zip Technologies, a third-party maker of accelerators for the Apple II, though Apple used separate chips instead of combining the processor, cache, and supporting logic on a multi-chip module as did Zip. Like later models of the original Apple IIc, the IIc Plus included a memory expansion slot that would accept a daughter-card carrying up to a mebibyte of RAM. The IIc Plus also featured a new keyboard layout that matched the Platinum IIe and IIGS. Unlike the IIe, IIc and IIGS, the IIc Plus came only in one, American, version, and was not officially sold anywhere outside the USA.

Many perceived the IIc Plus as Apple's attempt to compete with the Laser 128EX/2, a popular third party Apple-compatible machine that also had an accelerated processor and a built-in 3½" drive. There were few other rational explanations for Apple expending resources on the continued development of a new 8-bit Apple II model rather than furthering the 16-bit Apple IIGS. However, with its 3½" drive and speedy processor, it was an excellent, compact machine for running the AppleWorks integrated productivity package, especially with the 1 MiB memory upgrade.

Although not an extension of the Apple II line, in 1990 the Apple IIe Card, an expansion card for the LC line of Macintosh computers, was released. Essentially a miniaturized Apple IIe computer on a card (using the Mega II chip from the Apple IIGS), it allowed the Macintosh to run 8-bit Apple IIe software through hardware emulation (although video was emulated in software and was slower at times than a IIe). Many of the LC's built-in Macintosh peripherals could be "borrowed" by the card when in Apple II mode (i.e. extra RAM, 3½" floppy, AppleTalk networking, hard disk). The IIe card could not, however, run software intended for the 16-bit Apple IIGS. The Macintosh LC with IIe Card was intended to replace the Apple IIGS in schools and homes and was presumably the reason a new model Apple IIGS that was confirmed by insiders to be in development at one point was cancelled and never released.

Mike Markkula, a retired Intel salesman who provided early critical funding for Apple Computer, was keen on marketing. From 1977 until 1981 Apple used the Regis McKenna agency for its advertisements and marketing. In 1981, Chiat-Day acquired Regis McKenna's advertising operations and Apple used Chiat/Day. At Regis McKenna Advertising, the team assigned to launch the Apple II consisted of Rob Janov, art director, Chip Schafer, copywriter and Bill Kelley, account executive. Janov came up with the Apple logo with a bite out of it. The design was originally an olive green with matching company logotype all in lower case. Steve Jobs insisted on promoting the color capability of the Apple II by putting rainbow stripes on the Apple logo. In its letterhead and business card implementation, the rounded "a" of the logotype echoed the "bite"; in the logo. This logo was developed simultaneously with an advertisement and a brochure; the latter being produced for distribution initially at the first West Coast Computer Faire. Ever since the original Apple II, Apple has paid high attention to its quality of packaging, partly because of Steve Jobs' personal preferences and opinions on packaging and final product appearance. ^[8] All of Apple's packaging for the Apple II series looked similar, featuring lots of clean white space and showing the Apple rainbow logo prominently.^[9] For several years up until the 1980s, Apple used the Motter Tekkura font for packaging, until changing to the Apple Garamond font.

Apple ran the first advertisement for the Apple II in the July 1977 edition of Byte Magazine -- a two page spread ad titled "Introducing the Apple II" and followed by a third page that was an order form. The first brochure, was entitled "Simplicity" and the copy in both the ad and brochure pioneered "demystifying" language intended to make the new idea of a home computer more "personal." The Apple II introduction ad was later run in the September 1977 issue of Scientific American.^[10]

Towards the end of 1982, art director Brent Thomas and Steve Hayden came up with the idea of doing an ad campaign based on the timely tagline "Why 1984 won't be like 1984". Chiat-Day shopped it around to a number of clients, including Apple, where it was proposed to be used for a print ad in the Wall Street Journal promoting the Apple II. However, Apple didn't go for it, and the idea was filed away until the spring of 1983, when they met with the Macintosh marketing team to start working on the launch, which was scheduled for January 1984. The idea eventually became the famous 1984 commercial which aired during the Third Quarter at Super Bowl XVIII.^[12]

The Ace clones from Franklin Computer Corporation are the best known and had the most lasting impact, as Franklin copied Apple's ROMs and software and freely admitted to doing so. Franklin's argument: a computer's ROM was simply a pattern of switches locked into a fixed position, and one cannot copyright a pattern of switches. Apple fought Franklin in court for about five years to get its clones off the market, and was ultimately successful when a court ruled that software stored in ROM was in fact copyrightable. (See Apple Computer, Inc. v. Franklin Computer Corp.) Franklin later released non-infringing but less-compatible clones; these could run ProDOS and AppleWorks and had an Applesoft-like BASIC, but compatibility with other software was hit-or-miss.

Apple also challenged VTech's Laser 128, an enhanced clone of the Apple IIc first released in 1984, in court. This suit proved less fruitful for Apple, because VTech had reverse-engineered the Monitor ROM rather than copying it and had licensed Applesoft BASIC from its creator, Microsoft. Incredibly, Apple had neglected to obtain exclusive rights to the Applesoft dialect of BASIC from Microsoft; just as incredibly, VTech was the first cloner to bother licensing it. The Laser 128 proved popular and remained on the market for many years, both in its original form and in accelerated versions that ran faster than 1 MHz. Although it wasn't 100% compatible with the Apple II, it was close, and its popularity ensured that most major developers tested their software on a Laser as well on as genuine Apple machines. Because it was frequently sold via mail order and mass-market retailers such as Sears, the Laser 128 may have cut into the sales of low-cost competitors such as Commodore Business Machines as much as it did Apple's.

Bell & Howell, an audiovisual equipment manufacturer whose products (particularly film projectors) were ubiquitous in American schools, offered what appeared at first glance to be an Apple II Plus clone in a distinctive black plastic case. However, these were in fact real Apple II Pluses manufactured by Apple for B&H for a brief period of time. Many schools had a few of these Black "Darth Vader" Apples in their labs.

The "II" portion of the Apple II name was rendered in a variety of creative ways using stylized characters which resembled punctuation symbols on the front lids of the computers, and most printed material followed this lead. The II and the "unenhanced" IIe were labeled ][ and ][e, and the IIGS and IIc Plus were rendered in small caps. The Apple ///, IIc, and later IIe models used slashes: ///, //c and //e. There have been some errors in the Apple II's name due to the numerous variations and forms on the "II".

Today, emulators for various Apple II models are available to run Apple II software on Mac OS X, Linux, Microsoft Windows, and other operating systems. Numerous disk images of Apple II software are available free over the Internet for use with these emulators. AppleWin and MESS are among the best emulators compatible with most Apple II images. The MESS emulator supports recording and playing back of Apple II emulation sessions. The Home Action Replay Page (aka HARP) allows Apple II users to archive their favorite play sessions of the Apple II system and its games. However, many emulators cannot run software on copy-protected media, or can run only software employing fairly simple protection schemes, unless it is "cracked" (copy restrictions removed). Cracked software was widely pirated in the Apple II's heyday (with commercial cracking software such as the popular Copy II+ program being sold in stores with the purpose of "creating legitimate back-ups" of protected software), and some of it is still available, although use of such software is of questionable legality (see DMCA). For those who prefer to obtain their old software on the up-and-up, the Lost Classics Project has the goal of convincing copyright holders of classic Apple II software to officially allow unrestricted free distribution of their software and has "freed" a number of programs.

One unusual homage to the Apple II is an XScreenSaver "hack" named bsod. The bsod screensaver duplicates the appearance of computer crash screens for various operating systems (including the Windows Blue Screen of Death, after which it is named). In the case of the Apple II, the screensaver actually emulates the CRT display typically used with the computer, so the screen will appear to twitch as text blocks turn on and off, a common quirk of analog NTSC displays. Another module called "Apple2" shows a working Apple II being used to type and run three different programs in Applesoft BASIC, also with glitch-complete CRT emulation and even typos (or "syntax errors"), though the error messages are displayed at edit time (like Integer BASIC) instead of at run time (like Applesoft BASIC).

The Apple II series of computers had an enormous impact on the technology industry and on everyday life. The Apple II was the first computer many people ever saw, and its price was within the reach of many middle-class families. Its popularity bootstrapped the entire computer game and educational software markets and began the boom in the word processor and computer printer markets. The first microcomputer "killer app" for business was VisiCalc, the earliest spreadsheet, and it ran first on the Apple II; many businesses bought Apple IIs just to run VisiCalc, because it was the only spreadsheet available at the time. Apple's success in the home market inspired competitive home computers such as the VIC-20 (1980) and Commodore 64 (1982, with estimated sales between 17 and 25 million units). Through their significantly lower price point, these models introduced the computer to several tens of millions more home users, acquiring most of Apple's market share in the process.

The success of the Apple II in business spurred IBM to create the IBM PC, which was then purchased by middle managers in all lines of business to run spreadsheet and word processing software, at first ported from Apple II versions; later, whole new application software dynasties would be founded on the PC. The popularity of these PCs and their clones then transformed business again with LAN applications such as e-mail and later Internet applications such as Usenet and the WWW.

One valuable lesson from the Apple II was the importance of an open architecture to the success of a computer platform. The first Apple IIs shipped with an Apple II Reference Manual containing a complete schematic of the entire computer's circuitry and a complete source listing of the "Monitor" ROM firmware that served as the machine's BIOS (later this guide had to be purchased separately, and in the case of the Apple IIGS, the full technical documentation ran to several volumes). The Apple II's slots, allowing any peripheral card to take control of the bus and directly access memory, enabled an independent industry of card manufacturers who together created a flood of hardware products that let users build systems that were far more powerful and useful (at a lower cost) than any competing system, most of which were not nearly as expandable and were universally proprietary. Even the game port was unusually powerful and could be used for digital and analog input and output; one hacker used it to drive a LaserWriter printer.

Apple decided not to create an open architecture with the initial Macintosh models, and this is widely seen as having hobbled its success; however, the IBM PC provides an object lesson that success for the platform does not necessarily equate to success for the company that invented it. In the end, the IBM PC's off-the-shelf, open architecture allowed clones to be manufactured by startup competitors such as Compaq, Dell and Gateway, leading to a Pyrrhic victory for IBM. 2004年12月，IBM确定将其电脑部门－包括其所有型号及技术－以17亿5千万美元卖给中国的联想集团。^{[13] [14]}