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 MB of RAM without the bank-switching issues of previous models. It introduced two completely new graphics modes with higher resolutions and a palette of 4,096 colors; however, only 4 colors (at 640×200 resolution) or 16 colors (at 320×200 resolution) could be used on a single line at a time. The Apple IIGS distinguished itself from any other Apple II model before (or after), evolving and advancing the platform to the next generation of computing while still maintaining almost complete backward compatibility. The secret to the Apple IIGS's compatibility was a single chip called Mega II, which contained the functional equivalent of an entire Apple IIe computer (excluding the processor). This, combined with the 65C816 processor's flawless 65C02 emulation mode, guaranteed full support for legacy software. The computer also included an Ensoniq 5503 32-voice music synthesizer, based on "wavetable" samples with 64 KB of dedicated RAM, 256 KB of standard RAM, integrated peripheral ports (switchable between IIe-style card slots and IIc-style integrated controllers for disk drives, mouse, RGB video and serial devices), integrated AppleTalk networking and a ROM toolbox that supported a graphical interface derived from the Macintosh toolbox. The computer could run existing 8-bit Apple II software (including software written for the original Apple II in Integer BASIC), but also supported 16-bit software running with a new operating system initially called ProDOS 16 and later called GS/OS. The new operating system eventually included a Finder that could be used to manage disks and files and open documents and applications, along with desk accessories, just like the Macintosh. The 16-bit operating system automatically switched to text display and switched to 8-bit mode to run legacy software, while offering a coherent, Macintosh-like graphical interface for native 16-bit applications. Finally, 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 Unix-like shell), TrueType outline font support and, in one case, even real-time 3D gaming using texture mapping. The first 50,000 Apple IIGS computers came supplied with Steve Wozniak's "Woz" signature silk-screened on the front and were designated "Woz Limited Edition".
Source: https://en.wikipedia.org/wiki/Apple_IIGS ·
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