The system is a radical departure otherwise, with a WDC 65C816 microprocessor, 256 KB of random-access memory at launch expandable to 8 MB, resolution and color similar to the Amiga and Atari ST, and a 32 channel Ensoniq wavetable synthesis chip.

To exploit the IIGS's audio capabilities, during its introduction, Apple sold Bose Roommate amplified speakers for the computer (matching its platinum color and with custom Bose/Apple logo grille covers).

A more recent expansion option, the AppleSqueezer GS, combines an accelerator with adjustable speeds up to 14 MHz, 14MB RAM (240MB with drivers), and HDMI output all in a single package.

The first 50,000 Apple IIGSs manufactured had a reproduced copy of Wozniak's signature ("Woz") at the front right corner of the case, with a dotted line and the phrase "Limited Edition" printed just below it.

In the end, most users found that the upgrade did not save them much money once they purchased a 3.5-inch floppy drive, analog RGB monitor, and mouse.

Like the Apple II+, IIe, and IIc, the IIGS also includes Applesoft BASIC and a machine-language monitor (which can be used for very simple assembly language programming) in ROM, so they can be used even with no operating system loaded from disk.

In addition, a system called The Manager can be used to make the Finder more like the one on the Macintosh, allowing major software (other than just the "accessory" programs) to run simultaneously through cooperative multitasking.

The magazine added that "hog-tied by [classic] Apple II compatibility, [the IIGS] approaches but does not match or exceed current computer capabilities" of the Macintosh, Amiga, or Atari ST, and predicted that many vendors would "enhance existing products for the [classic] Apple II instead of writing new software" that fully exploited the IIGS's power.

described the IIGS in November 1986 as "two machines in one—a product that bridges the gap between the Macintosh and Apple IIe, and in so doing poses what may be serious competition for the Commodore Amiga and the Atari ST series".

The magazine stated that many customers either chose the slightly more expensive Macintosh Plus or kept their inexpensive IIc or IIe which ran AppleWorks well, with the IIGS "in a strange position" in between.

[22] BYTE's Bruce Webster in January 1987 praised Apple for permitting Wozniak to finish the IIx project, but said that the company should have done so "a few years ago".

The other computers, he wrote, have both larger software libraries that use their power and lower prices; Webster found that a IIGS package costing $2,500 was comparable to a $1,500 Atari ST configuration.

"[23] A BYTE review in April 1987 concluded that the IIGS "has the potential to be a powerful computer" but needed a faster CPU and more addressable memory.

The magazine advised potential customers to compare the Macintosh, Amiga, and Atari ST's more powerful 68000 CPU with the IIGS's greater expandability and large Apple II software library.

in 1988 urged Apple to make the computer faster, stating that "no matter which way you cut it, the IIGS is slow" and that IIGS-specific programs could not keep up with user actions.

"[25] It reported that year that after increases in September, a IIGS with color monitor, two disk drives, and ImageWriter II cost more than $3,000, a price the magazine called "staggering".

reported that both Cinemaware and Intergalactic Development had to write their own tools to maximize their use of IIGS audio, with the latter stating that "these sorts of problems … are becoming well-known throughout the industry".

It is rumored that several prototypes that greatly enhanced the machine's features and capabilities were designed and even built, though only one has ever been publicly exposed (i.e. the "Mark Twain").

Specifically, the 80-column text display and monochrome double-high-resolution graphics had a symptom wherein small flickering or static pink bits would appear between the gaps of characters and pixels.

In August 1987, Apple released an updated ROM that was included in all new machines and was made available as a free upgrade to all existing owners.

This update also allows up to 8 MB for the RAM Disk, added some new features for programmers, and reported the ROM version and copyright information on the startup splash screen.

Hardware shadowing of Text Page 2 was introduced, improving compatibility and performance with the classic Apple II video mode.

The clock battery is now user-serviceable, being placed in a removable socket, and a jumper location was added to lock out the text-based control panel (mainly useful in school environments).

The consistent use of the new corporate color and matching peripherals ushered in the Snow White design language, which was used exclusively for the next five years and made the Apple product line instantly recognizable around the world.

As part of an earlier trademark dispute with the business arm of The Beatles, Apple Computer had agreed not to release music-related products.

[40] However, the educational community had a substantial investment in the IIGS software as well, which made upgrading to a Macintosh a less attractive proposition than had been for the Apple IIe.

[44] Nevertheless, seeing the need to help switch their educational customers to the Macintosh (as well as sell Power Macs), Apple unofficially distributed the software for free to schools and other institutions that signed a non-disclosure agreement.

Gus represents one of the few software emulators developed within Apple (officially or otherwise), including MacWorks and Mac OS X Classic environment.

reported on speculation that Apple would announce at the May AppleFest a "IIGS Plus" with a processor two to three times faster, 768 KB to 1 MB RAM, and a SCSI port.

[citation needed] Cirtech produced a working prototype of a black-and-white Macintosh hardware emulation plug-in card for the IIGS dubbed "Duet".