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Info for a400


====== Atari 400 Home Computer (1979) ======




===== Features =====

* CPU: MOS 6502 1.79MHz
* Co-Processors: ANTIC (Scrolling, Sprites, Video), CTIA / GTIA (Color, Sprites, Collisions), POKEY (Timers, Sound, Keyboard, Serial I/O), PIA 6810 (I/O including controller ports)
* RAM: 8K or 16K (newer models)
* ROM: 10K
* Display: 24 x 40 text, 320 x 192 monochrome, 160 x 96 with 128 colors
* Expansions: 2 internal expansion slots, 1 cartridge slot under front cover and a daisy-chainable expansion bus
* Ports: 4 controller ports
* Keyboard: QWERTY membrane keyboard with 61 keys, 4 function keys (Reset, Option, Select, Start)
* TV video output
* Storage: external 5.25" floppy drive, cassette recorder
* OS: Atari OS



===== Usage =====

Currently, MESS supports the following Atari 400 versions:

* a400 [Atari 400 (NTSC)]
* a400pal [Atari 400 (PAL)]

Both drivers support cart dumps in .rom and .bin format, using the "cartridge" (cart) device, and up to four floppy drive for disks in .atr, .dsk and .xfd format, "floppydisk1" (flop1) to "floppydisk4" (flop4).

== Keyboard ==

These systems require full keyboard emulation to work correctly. At startup, full keyboard emulation mode is enabled by default. Whilst in full keyboard emulation mode, some key associated functionality may be disabled (like the ESC key for EXIT). The keyboard emulation mode is toggled using the "Scroll Lock" key (by default).

Original Keyboard: QWERTY, 61 keys plus 4 function keys on the right

CLEAR INSERT DELETE SYSTEM
ESC 1! 2" 3# 4$ 5% 6& 7' 8@ 9( 0) < > BACK S BREAK RESET

CLF SET UP _ DOWN |
TAB Q W E R T Y U I O P - = RETURN OPTION

LEFT \ RIGHT ^ CAPS
CTRL A S D F G H J K L ;: + * LOWR SELECT


SHIFT Z X C V B N M ,[ .] /? ATARI SHIFT START


SPACE

Keys "TAB", "-", "=", "+" and "*" have 3 functions.



===== Known Issues =====

Most disk and cartridge images should work, though some graphic issues may exist. Note that the Atari 400 has less memory than the Atari 800, and some disk images may not work as a consequence; this is not a bug in the emulation.



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

The Atari 400 and 800 were the first home computers to use custom coprocessors and the first to use "sprites" and special video interruptions like display lists, features that will be implemented several years after on the Commodore Amiga. It offered high graphic resolution, lots of colors and great sound capabilities, more than other computers could do then! The two models had same characteristics, the 400 is the low-cost version, it has only 16 KB (instead of 48 KB), one cartridge port (two for the 800) and a membrane keyboard (a typewriter style keyboard one for the 800).

Originally, the 400 was sold with 8 kb RAM, but later most 400's with 16 kb.

The Atari 400 was known inside Atari as code name "Candy".

//(info from old-computers.com)//



===== Links =====

* Atari 400 at the Atari Hystory Museum -- http://www.atarimuseum.com/computers/8BITS/400800/400/400.html
* Atari 400 at vintage-computer.com -- http://www.vintage-computer.com/atari400.shtml
* Atari 400 at old-computers.com -- http://www.old-computers.com/museum/computer.asp?c=76



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

* Atari800 (Unix, Amiga, MS-DOS, Atari TT/Falcon, SDL, WinCE) -- http://atari800.sourceforge.net/
* Atari++ -- http://www.math.tu-berlin.de/~thor/atari++/
* Atari800Win Plus -- http://www.a800win.atari-area.prv.pl/
* Rainbow (historical) -- http://www.chrislam.co.uk/
* PC Xformer (historical) -- http://www.emulators.com/xformer.htm




Generated on Sun Jul 19 10:17:28 2009