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Old 23 August 2001, 23:47   #5
Give up the ghost
Join Date: Apr 2001
Location: U$A
Age: 26
Posts: 4,662
OK, you will have to excuse (or ignore) the long text description below (from Byte Magazine), which explains how Akira is not completely wrong, as the IIGS retained compatibility with the previous 8-bit Apple II systems:

Here are the most important features of the Apple lI GS: Apple II
compatibility: The Apple II GS will run most Apple II software and
expansion cards. It can run at normal Apple II speed or at a higher
rate that makes most software run two to three times faster. [ Edit
or's note: In this article, "Apple II" refers to the traditional Apple
II computer as defined by the Apple II, II+, lIe, and IIc. ] The Apple
II GS composite video signal has been corrected so that it will be
recorded correctly by a videotape recorder. Apple lie owners can
upgrade to complete II GS compatibility by replacing the motherboard
and back/bottom plate with a II GS retrofit kit. A 16-bit,
6502-compatible processor: With a 16-bit address bus and 8 "bank
address" lines, the Western Design Center's W65C816 can address 256
banks of 64K bytes each, for a total of 16 megabytes. It can also go
into a 6502 mode, where it emulates the 65C02A used in the Apple lIe
and IIc. The processor's accumulator, stack pointer, and all its
registers are 16 bits wide, and its instruction set includes 11 new
addressing modes. Greatly expanded memory capacity: The machine's
architecture reserves space for 8 megabytes of user RAM and 1 megabyte
of system ROM. It comes with 256K bytes of RAM, 128K bytes of system
ROM, and 64K bytes of dedicated sound-wave-form memory, but you will
have to wait for new programs to use most of the memory above the first
128K bytes. Apple currently has plans for 1- and 4-megabyte expansion
cards, although an 8-megabyte card is possible. New graphics
capabilities: The Apple II GS adds 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 come from a color set of 4096. The machine
can use up to 16 palettes per screen and change palettes and resolution
on a line-by-line basis. Programmers can use two experimental modes: a
640- by 200-pixel, 16-color (with restrictions) palette mode, and a
high-speed "fill mode" variation of the 200 by 320, 16-color mode. New
sound capabilities: The 32-voice Ensoniq Digital Oscillator Chip (DOC),
used in the Ensoniq Mirage sampled-sound music synthesizer, and system
firmware can drive the chip to prod uce up to 15 musical "instruments."
Mouse, keyboard, and disks: A one-button mouse and a detachable
keyboard with keypad are standard equipment. The Apple II GS does not
have an internal disk drive, but you can daisy-chain up to two
800K-byte 3-1/2-inch drives and two 140K-byte 5-1/4-inch drives to the
disk drive port on the rear panel. The system software will come on
3-1/2-inch disks, which silently but forcefully indicates Apple's
intent to phase out the 5-1/4-inch floppy disk. The Toolbox:
Application programs can use built-in code (some in ROM, some in RAM)
to provide a mouse-driven desktop environment and orderly use of system
resources. The Finder: Finder software, supplied with the basic system,
allows users to interact with disks and files using windows, icons, and
a mousedriven cursor (as popularized by the Apple Macintosh). Desk
accessories: The Apple II GS makes available Macintosh-like desk
accessories; some a re available from all programs, and others work
only with programs specifically designed for the Apple II GS. The
Control Panel, accessible from any program, allows the user to change
the date, slot assignments, operating speed, and similar parameters.
New languages and tools: For the software developer, Apple will offer a
6502/65C02/65816 assembler and versions of C and Pascal; the three
languages share a standard editor and linker and allow object code
modules from any source to be used together. For the hobbyist, Apple
has extended the Apple IIe monitor to work in the Apple II GS 16-bit
environment and has added new functions to it. No enhanced, built-in
language: Like the Macintosh (and unlike most other computers), the
Apple II GS contains no built-in language (such as Microsoft BASIC)
that interacts with the machine's new features. Applesoft BASIC is
available in system ROM, but it has no way of directly interacting with
the new Apple II GS features. A new 16-bit operating system: ProDOS 16
extends Apple's ProDOS (which runs on the Apple II+, IIe, and IIc) to
be the standard Apple II GS operating system; it runs on the 65816 in
native 16-bit mode, is functionally similar to the 8-bit ProDOS, and
shares an identical file structure with ProDOS. Apple has also made
slight modifications to the 6502-based ProDOS so that it will run on
the Apple II GS's Apple II emulation mode; this operating system is
named ProDOS 8.
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