====== Atari Mega ST (1987) ======
===== Features =====
* CPU: Motorola MC 68000 8 mHz
* RAM: 1 / 2 / 4 MB
* ROM: 192 KB
* Text Modes: 40 or 80 chars. x 25 lines (bitmapped graphics)
* Graphic Modes: 320 x 200 / 640 x 200 / 640 x 400
* Colors: 16 (320 x 200), 4 (640 x 200), monochrome (640 x 400) among 512
* Sound: 3 channels, 8 octaves programmable sound generator
* I/O Ports: Cardridge, Midi (in, out), Centronics, RS232c, Hard Disk, Floppy disk, RGB, Joystick, mouse
* Built In Media: 3.5" 360 KB disk-drive
* OS: TOS + GEM
===== Usage =====
MESS currently supports for the Mega ST both cart dumps and disk images. The former are accepted in .stc format and use the "cartridge" (cart) device; the latter are accepted in .st format and use one of the two floppy drives, "floppydisk1" (flop1) and "floppydisk2" (flop2).
Also notice that the "printer" (prin) and the "serial" (serl) port are emulated as well.
== Keyboard ==
This system requires 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).
=== BIOS options ===
Different versions of the TOS roms are supported. You can switch between them, changing the -bios parameter. At command line,
"-bios 0" or "-bios default" = TOS 1.04 (Rainbow TOS)
"-bios 1" or "-bios tos102" = TOS 1.02 (MEGA TOS)
=== RAM options ===
Different RAM configurations are possible for the megast in MESS. You can switch between them, changing the -ramsize parameter. At command line
mess megast -ramsize ram_value
where //ram_value// can assume one of the following values
1m - to emulate a Mega ST 1
2m - to emulate a Mega ST 2
4m (default) - to emulate a Mega ST 4
===== Known Issues =====
The emulation of this system is Preliminary.
===== History and Trivia =====
The Atari Mega ST was the "professional" version of the Atari STf (i.e. later version of Atari ST with built-in floppy drive).
Atari added the "Blitter", a custom chip designed to perform quick memory moves and increase display speed. The Mega ST had a small battery to hold time and date and a small fan (except for the Mega ST1).
This computer was especially designed to be the cheapest publishing solution (and it was!).
The Mega ST had a pretty good success and was replaced by the Mega STe and by the TT.
//(info from old-computers.com)//
===== Links =====
* AEX / Atari Explorer -- http://www.atari-explorer.com/index.html
* The Atari Historical Society -- http://www.atarimuseum.com/
* Atari Mega ST at old-computers.com -- http://www.old-computers.com/museum/computer.asp?c=165
===== Other Emulators =====
* Gemulator -- http://www.emulators.com/download.htm
Generated on Sun Jul 19 10:17:28 2009