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Info for apple2gs


====== Apple ||GS (1986) ======


===== Features =====

* CPU: Western Design Center 65C816 (16 bit) 2.8 MHz, switchable to 1 MHz
* RAM: 128 KB (ROM 0, ROM 1) or 1 MB (ROM 3), expandable to 8 MB
* ROM: 128 KB (ROM 0, ROM 1) or 256 KB (ROM 3), expandable to 1 MB
* Text Modes: 40 or 80 chars x 25 lines
* Graphics Modes: 320 x 200 / 640 x 200 + Apple II graphic modes (see below)
* Colors: 4096
* Sound: Ensoniq ES5503 32-voice wavetable synthesizer. The ES5503 was designed by Bob Yannes after leaving Commodore and it's the true sequel to the C64's SID chip. The 5503 has 64k of dedicated wavetable RAM in the ||GS. The ||GS also retains the speaker toggle of previous Apple IIs.
* I/O Ports: 7 slots, memory expansion, RS422c (2), analogue RGB, Apple Desktop Bus (mouse & keyboard), Composite video, joystick, audio, disk port, AppleTalk
* Keyboard: Detached 80-key full stroke with 10-key numeric pad and ADB pass-through port for the mouse.
* Built In Media: None.
* OS: All 8-bit Apple II OSes plus ProDOS 16 (a 16-bit translation layer over ProDOS, similar to how Windows 9x rode on top of DOS) and later GS/OS, a full 16-bit native OS with much better performance and advanced features like hot-swappable device drivers and plug-in filesystem modules to read CD-ROMs, MS-DOS FAT disks, and Macintosh HFS disks. The ||GS also included a full port of the Macintosh's "Toolbox" - GUI applications written in a high-level language such as C or Pascal were relatively easy to port aside from the endian and screen resolution differences. In fact, the IIgs was the first Apple released with a color version of the Mac UI (although the Mac II followed it very closely).



===== History and Trivia =====

The Apple ||GS was originally the "IIX" project, which was intended to use the 65816 along with a special slot that could be used to add either an 8088 (for PC compatibility) or a 68000 (to run Mac software). But the 65816 was running late (William D. Mensch famously laid it out by hand on his kitchen table, using no computer assistance) and Apple management killed the project.
It was later resurrected under the codename "Phoenix" (and later "Gumby" and "Rambo") when the 65816 was ready, and it did make it to market despite a lukewarm response from Apple management. The ||GS was made possible by the development of the "Mega II" ASIC, which contained the entire circuitry of an enhanced Apple IIe except for the CPU, ROMs, and RAM on a small single chip, but it was Steve Wozniak himself who gave a crucial boost to the engineers, coming up with a scheme that would maintain very high Apple II compatibility while still letting the ||GS be its own machine.
In tribute, the first production run of the ||GS had Woz's signature stamped onto the case.

Sales were strong initially and the ||GS even outsold the black and white Macintosh units that were its contemporary. The ||GS was the first Apple released that could show the Mac GUI in color and the first released machine with the new ADB peripheral connection (the Mac II and SE were introduced several months later). Apple management was terrified of hurting Mac sales so they had forced the engineers to run the 65816 much slower than the 7 MHz 68000 of the Mac Plus (Wozniak and the engineering team had wanted to run the 65816 at 8 MHz). Even so, the ||GS's all-assembly language Toolbox was eventually tuned to the point where even at 2.8 MHz the GUI felt as snappy as its more powerful cousin. The slow CPU did hurt it for games though - games on the ||GS typically looked good and sounded great but animated poorly. The Apple ||GS disappeared from the market in 1992.

In one final gasp, the Apple II supporters at Apple designed the Apple ||GS Plus, code named "Mark Twain". It was rumored to have an 8 MHz 65C816, a built in SuperDrive, 2MB on the motherboard, and a hard drive. Apple management originally green lighted the new machine and reserved time during a satellite broadcast in September of 1991 to introduce it to the world, but it was killed at the last minute due to the usual objections that it could hurt the Macintosh.
A prototype leaked out of Apple years later and was much less ambitious than was originally thought: it contained the same ROM 3, but with 2 MB of RAM, an on-board SCSI controller, and an internal SCSI HDD. So even if it had been introduced it would have been too little too late.

The Ensoniq chip in the Apple ||GS was a brilliant move by Apple, but like a lot of things related to the ||GS it was something of an accident. Although the 5503 powered several successful Ensoniq synthesizers (the ESQ-1, SQ-80, and the Mirage sampler), Bob Yannes remembered the impact of his SID on the Commodore 64 and wanted to get the chip into a computer. He first called Commodore, but
they weren't interested in chips they didn't make (they also passed on the 65816 CPU - imagine a C64 sequel with the 65816 and 5503!) He called Apple and got bounced around to various people until it hit an engineer on the ||GS team who was heavily into electronic music. As usual getting management to accept the chip was an uphill fight - originally the sockets for the 5503 and its RAM were to be
placed on the board and the chips sold separately, but finally they realized the cost difference was minor at that point and included the chips in every machine sold. It was so close that the system software shipped with an error code defined for "Ensoniq not present".

The chip also caused legal trouble with Apple Records, which resulted in Apple never again putting a hardware synthesizer chip into a computer. The Macs relied on a 4-voice DMA setup similar to the Commodore Amiga for years and now just use software synthesis.

The "SmartPort" external drive port supports both Apple IIe/IIc UniDisks (3.5" and 5.25" models) and the newer Apple 3.5 Drive which was shared with the Macintosh. You could have a total of 2 UniDisks and 4 Apple 3.5 Drives daisy-chained, although such a configuration would have put quite a strain on the stock power supply. Some companies also made SmartPort compatible harddisks, but these were relatively slow and most ||GS users used an add-on SCSI card and drive instead.

The difference between a UniDisk and a ||GS 3.5" drive is that the IIGS drive is controlled directly by the computer while the UniDisk has a separate processor. The UniDisk is thus much slower (up to 4x slower) than a ||GS 3.5" drive.

Apple and third parties both sold SCSI cards for the ||GS, and Applied Engineering sold a "high density" floppy drive that got double the density by spinning the disk at half speed. There was never any official Apple support for the more conventional 1.44 MB SuperDrives that were used with the Mac - those required the newer "SWIM" controller chip, while the IIgs still had only the original "IWM" (shared with Macs up through the Mac Plus).

The ||GS was available initially as an upgrade motherboard for the Apple IIe - you got a board which would fit in the IIe case and had connectors for the IIe's power supply and internal keyboard and replacement stickers which changed the old "Apple" and "IIe" in Apple's original font into "Apple IIgs" in the newer Apple font. All the other connectors were still present, and you could buy an ADB keyboard and mouse to use with it as well. A IIe upgrade version of the ROM 3 motherboard was never made however.

The initial ROM 0 ||GS shipped with defects in the "Video Graphics Controller" custom ASIC that caused fringing in the old Apple II video modes under some circumstances. A new VGC and a new ROM chip were a free upgrade to bring those systems up to ROM 1 specs.



== Graphic Modes ==

The Apple ||GS had a lot of graphic modes. All modes used a 12-bit palette for 4096 colors.

* 320x200 with 16 colors per scanline. There were a total of 16 hardware palettes that could each be assigned to one or more scanlines, making 256 colors on screen possible at once. Later software discovered that there was (barely) enough CPU time to rewrite the palette as the beam marched down the screen, giving 16 unique colors on each scanline and up to 3200 colors on screen at once (similar to the Amiga's HAM mode, but more limited).
* 640x200 with 4 colors. The pixels were small enough in this mode that adjacent pairs of pixels blended to create the illusion of 16 colors, although this of course effectively reduced the effective resolution for things which weren't in black and white. Most apps using the GUI Toolbox ran in this mode, although the aspect ratio was pretty terrible.
* Fill mode can be enabled on scanlines which are in the 320x200 mode. This makes color 0 repeat the last non-0 color present on the scanline, making it possible to draw filled polygons at a much higher speed than would otherwise be possible. It was used mostly in a few Eurodemos and a port of the Amiga game "Out Of This World".
* Each scanline could independantly be in 320 or 640 mode, although such mixes weren't commonly seen. A per-scanline interrupt was also available for raster effects (such as the "3200 color" mode).
* SVGA modes with 24-bit color could be added with a 3rd party VGA card, but it came late in the life of the ||GS and had little software support.

The ||GS also had all the graphics modes found on the //c.

* Text mode: 40x24 and 80x24. Characters are formed by a 7x8 pixel matrix. Text mode is monochrome but can be set to a specific color. The background and border can each be set to different colors. Text mode is rarely used in GS programs since the OS, GS/OS, had a graphic desktop.
* Low Resolution: 40x48 pixels in 16 colors. Double Low Resolution: 80x48 pixels in 16 colors.
* High Resolution: 280x192 pixels in 6 colors Double High Resolution: 560x192 pixels in 16 colors.
* Combinations/Variations: 4 lines of text mode could be mixed with a truncated Low Resolution or High Resolution mode graphic. The text in mixed mode could be either 40 column or 80 column. Double Low Res and Double High Res modes couldn't be mixed with text.

//(info from old-computers.com and other sources)//

== Apple "][", Apple "II", Apple "//" : which is correct? ==

"][", "II", and "//" tend to be used pretty much interchangeably for any model of Apple II computer, although, practically speaking, there are a few usages which may provoke a correction.

"][" is the original Apple II symbol. It appears on all early II's and II+'s as well as on the Disk ][ drive. It is, easily, the most attractive and distinctive II symbol; but, it is also associated with old Apple II's. The "//" usage is generally associated with the "c" and newer "e" models.

The generally preferred machine designations are:

* Apple ][ or Apple II for pre-][+ models
* Apple ][+ or Apple II+
* Apple IIe for non-enhanced IIe computers
* Apple //e for 128k-enhanced IIe computers
* Apple //c
* Apple IIc+
* Apple IIgs or GS or best (if you have the fonts) ||GS

== Easter Egg ==

The ||GS with ROM version 3 has an audio recording built-in. Upon booting, when you see the "Open Apple" move back and forth on the screen, press <Control> <Open Apple> <Option> <N>. You will hear the ||GS design team shouting "Apple II!", and see the designers' credits.

ROM 1 has the same Easter Egg without the audio clip due to its smaller ROM.



===== Links =====

* A2central.com -- http://www.a2central.com/
* Apple2.org (pictures of Apple II and other related hardware, articles, the Apple ][ FAQ, and lots more) -- http://www.apple2.org/
* Forever 1970..80..90 (Very complete information for each model) -- http://perso.wanadoo.fr/fabrice.montupet/
* Apple II - Apple II gs (A lot of documentations here!) -- http://www.apple-iigs.info/home.htm
* CSA2 Usenet Apple II FAQs and Links -- http://home.swbell.net/rubywand/A2FAQs1START.html
* Ninjaforce (Makers of demos for the Apple IIGS, including the Ninjaforce Mega Demo) -- http://www.ninjaforce.com/
* Free Tools Association (The premiere IIgs demo group, based in France. They offer downloads of their productions plus a version of KEGS that runs as an Active X control inside Internet Explorer) -- http://www.freetoolsassociation.com/
* What is the Apple IIgs? -- http://www.whatisthe2gs.apple2.org.za/
* Apple IIgs at old-computers.com -- http://old-computers.com/museum/computer.asp?c=71



===== Other Emulators =====

* XGS (Windows, DOS, Mac, NeXT - now discontinued) -- http://www.inwards.com/xgs/
* KEGS (For Mac OS X, Win32, Linux, and Unix/X11 - extremely accurate) -- http://kegs.sourceforge.net/
* KEGS32 (Win emulator based on the Kent Dickey's KEGS for UNIX) -- http://www.geocities.com/akilgard/kegs32/
* Bernie II the rescue (The most fully featured IIGS emulator, only on the MacOS for PowerPCs) -- http://www.bernie.gs/Bernie/




Generated on Sun Jul 19 10:17:28 2009