Apple introduced the Apple IIgs in September 1986. It was intended to be a replacement for the venerable Apple IIe that was the mainstay of Apple's revenues for most of the early part of the 1980s. The Macintosh was changing the world and would soon replace the Apple II as the company's cash cow, but many Apple II faithful still longed for an advanced version of their beloved computer. Although strictly speaking, the Apple IIc Plus was the last Apple II computer introduced by Apple, the IIgs is arguably the most advanced and for many, it represents the pinnacle of the Apple II family.
The Apple II has a curious history. It was originally designed by Steve Wozniak in 1976 as a homebrew computer that squeezed the maximum features out of minimum parts. Over the years, it evolved into the Apple II Plus, then the IIe, then the IIc. Apple tried to kill it off with the Apple III, which failed to reach widespread acceptance and died itself. Despite Apple's attempt to move the company in total over to the new Macintosh standard, the popularity of the Apple II was too great to ignore. Apple knew that the Apple II family of computers was antiquated by 1985, but the company just could not discount the fact that the Apple II, which had been in production since 1977, had a massive following along with a massive collection of available software.
By mid-1985, the Apple II began to lose its sales appeal, and Apple engineers, assisted by Steve Wozniak (who was asked to help with the effort) were already working on a project called, at various times, Phoenix, Columbia, Cortland, and Granny Smith: the Apple IIgs. The IIgs project simultaneously took a look back to the past and forward to the future. The machine could best be summarized by saying that it took a giant leap in both directions.
The Apple IIgs could run most Apple II software and expansion cards. Despite the considerable difference in memory size and other features, most of the programs originally designed for the first generation of Apple computers could run on the IIgs. This compatibility was a result of a commitment to compatibility among the computers of the Apple II family. The IIgs could run at normal Apple II speed (about 1 MHz) or at a higher rate (about 2.8 MHz). Even in 1986, the Apple IIgs' 65C816 processor was considered inadequate for many high-end computer applications.
The IIgs offered greatly expanded memory capacity over the IIe. The machine's architecture reserved space for 8 MB of user RAM and 1 MB of system ROM, but Apple never produced a IIgs with more than 256K onboard ROM. At its introduction, the IIgs came with 256K onboard RAM. The last version of the IIgs, ROM 3 released in 1989, had 1 MB of onboard RAM. The Apple IIgs motherboard had a special memory-expansion slot designed for a card with up to 8 MB of RAM.
The "gs" in IIgs stood for "graphics and sound." Its expanded capabilities brought the Apple II family in line with many top computer systems of its day. Some would argue that the Apple IIgs far outperformed the original Macintosh all-in-one computers in terms of graphics and sound. The emphasis on graphics and sound was a remarkable break from previous Apple II computers. Where in the past, the Apple II was a generalized computer system that did a little of everything, the IIgs was a specialized graphics and sound system.
The IIgs had two "super hi-res" graphics modes: 200 by 320 pixels with a 16-color palette and 200 by 640 pixels with a 4-color palette. The colors came from a color set of 4096. The machine could use up to 16 palettes per screen and change palettes and resolution on a line-by-line basis. Because the IIgs emulated the Apple II, it contained all the Apple II text and graphics modes. The IIgs had a Video Graphics Controller (VGC) that implemented both old and new video modes as well as unrelated functions for the built-in clock chip, the disk drives, the interrupt system, and built-in chip and board testing routines. The VGC enhanced text modes by allowing the user to choose from the Control Panel the color (or gray scale value) of the text, its background, and the border outside the active text/graphics area.
The IIgs' digital oscillator chip offered exciting sound capabilities. The 32-voice Ensoniq Digital Oscillator Chip (DOC) used in the Ensoniq Mirage sampled-sound music synthesizer and system firmware could produce up to 15 musical "instruments". The DOC was attached to its own personal bank of 64K memory into which programs could store wave tables that the DOC used to generate sound.
The early Apple II computers had a keyboard built into the main processor unit. With the introduction of the IIgs, Apple followed the Macintosh formula of offering a detached ADB (Apple Desktop Bus) keyboard and mouse, but unlike the Macintosh, the IIgs did not have an internal disk drive. The Apple Desktop Bus was also used for generalized connection of up to 16 input devices daisy chained to a single connector on the back of the computer. It supported multiple keyboards (for education purposes) and a mouse (ending the daisy chain), but the design could accommodate other kinds of devices. The ADB was controlled by a dedicated 8-bit processor called the ADB microcontroller.
The Apple II was almost completely described by its hardware features. The IIgs ended this tradition with the inclusion of significant amounts of system software in both ROM and RAM meant to be available to all programs. It was not incidental that these routines were similar in name to those in the Macintosh computer. The Mac toolbox was an elegant, powerful, and proven system. The IIgs toolbox implemented the most useful Macintosh toolbox functions its 16-bit architecture could handle.
Before the introduction of the IIgs, Apple had crowned ProDOS as the operating for the Apple II line of computers. Although many 8-bit ProDOS programs could run on the IIgs, Apple developed ProDOS 16 specifically for the IIgs' 16-bit processor. Along with the new operating system, Apple implemented the IIgs Finder, which was a faithful imitation of the Macintosh desktop interface with a few exceptions. For example, unlike the Macintosh, an early version of the IIgs Finder had a "Special" menu that contained a new item - "Check Drives." This command caused the Finder to update its knowledge of what disk was in each drive. In early Apple II systems, a user could change the floppy in the disk drive without the computer knowing what had happened. Later versions of the IIgs Finder automated the process with a constant call to each disk drive (3.5 inch drive or 5.25 inch drive).
Special Menu in later version of Finder (Apple Inc.)
The IIgs used desk accessories similar to those in the Macintosh. A desk accessory is a mini-application that could be run from within another program (See PNG Floyd on VAW for an example of a desk accessory). The IIgs supported two types of desk accessories: classic desk accessories (CDA) and new desk accessories (NDA). A classic desk accessory could be activated only by the press of the keyboard and could be run with older Apple II programs. A new desk accessory ran only in the IIgs desktop environment and was available from a pull down menu, similar to a Macintosh Apple Menu item. The Control Panel was a classic desk accessory built into the IIgs. A user called up the Control Panel by simultaneously pressing open-apple-control-escape. The Control Panel allowed a user to set the speed of the processor, the color of the text and background, the responsiveness of the keys on the keyboard, the volume of the speaker, and the configuration of the slots.
The IIgs had many of the same ports found on the Macintosh SE, a printer port, a modem port with AppleTalk support, and a disk drive port. It also included a special analog RGB monitor port. Apple felt that an analog monitor would be more compatible with earlier Apple II software while still allowing the IIgs to show off its remarkable graphics capabilities. The IIgs was officially compatible with the 12-inch Apple RGB Monitor A2M6014, but there were several available third party monitors capable of displaying the IIgs' fairly low horizontal sync rate of 15.75 KHz. The IIgs also had a composite video port, but composite monitors were generally inadequate and could not properly display the IIgs' enhanced desktop environment.
The IIgs had seven expansion slots, like the IIe. The slots were almost identical in function to the Apple IIe's slots. Associated with each I/O expansion slot were built-in circuits and firmware that formed an "invisible" port. These invisible ports corresponded to the built-in ports mentioned above. The default settings for all the seven ports was as follows:
It was as though you had an Apple IIe with boards for all the above devices already plugged in. Unfortunately, this wealth of built-in interfaces carried with it some restrictions, the most severe being that if you had an expansion board you wanted to run in your IIgs, you had to give up the built-in port of whatever slot you plugged the board into. You would use the Control Panel to choose whether a slot was using its associate default port or plug-in board and this information was retained in the battery-backup RAM.
The Apple IIgs was the end of the line for the Apple II family of computers. It was a remarkably specialized machine. It had all the functionality of the original Apple II and yet was able to look to the future with its graphical operating environment and specialized graphics and sound firmware. The IIgs designers' achievements were impressive, but the burden of the classic Apple II architecture weighted them down and perhaps denied them any technological leaps beyond an exercise in miniaturization. The 16-bit 65C816 processor was a mixed blessing. It provided a means of supporting the Apple II's 6502 processor within a 16-bit mode, but it represented yet another set of oddities that programmers had to deal with. The IIgs affirmed several contemporary trends in microcomputer design: improved graphics and sound, larger processor and memory capacity, and the use of a mouse and graphical user interface. The machine also followed the Macintosh style of including large amounts of system firmware that was as important as the IIgs' hardware features. The IIgs, hogtied by Apple II compatibility, approached but did not exceed contemporary microcomputer capabilities. The Apple IIgs was an attempt to carry on the legacy of the Apple II by imitating many of the advanced features of the Macintosh. In hindsight, it was really just a matter of time before Apple moved on to concentrate exclusively on the Macintosh platform. Supporting two competing lines of computers was never a long-term goal for Apple, but one can take solace in the fact that Apple treated Apple II fans with one last ride on the Apple II train before it quietly pulled into the station for the last time.