TOSBOX
The Atari ST Emulator

TOSBOX provides an environment for running TOS and GEM applications under DOS or Windows.  It uses an operating system image which you can create on your actual Atari machine, and operates with most of the PC's peripherals.

The design of TOSBOX is unique in working from the system down rather than from the hardware up.  The goal was not to make a PC behave as exactly as possible like an ST, but to run Atari applications as smoothly as possible on a PC.  Whenever possible, system calls were redirected and translated; then, in cases where that failed to be reliable, the behavior of the actual hardware behavior was emulated.  The resulting product is able to run a considerable variety of popular software.

TOSBOX emulating Atari ST with Thing Desktop
Photo courtesy of the UK TOSBOX Mirror.  Click on image to enlarge

TOSBOX is not a complete hardware-level emulation of an Atari ST.  As such, it is not intended to run games and graphics demos.  For that, the author suggests using PaCifiST, by Frederic Gidouin.

The CPU emulation core is written in assembly language, and its speed on a Pentium 75 is typically about twice that of a stock STf, depending on the task.  Because of the design objectives described above, TOSBOX does a disproportionate amount of its work in the PC domain rather than in CPU emulation, so in practical terms it generally works faster than the numbers would suggest.

You need ordinary VGA graphics (though an SVGA card that complies with VESA 1.2 or higher is recommended), a mouse and mouse driver, at least 2 megs of memory, and a hard drive. Because TOSBOX runs in 32-bit protected mode, you also need a '386 or newer processor.   Finally, you need a TOS image file derived from your Atari computer.   ROMIMAGE.TOS, included in this archive, will make that for you.

Supported TOS versions include 1.00, 1.04, 2.05 and 2.06.  According to user feedback, TOS 1.02, 1.06, 1.62 and an enhanced 2.06 called "SUPERTOS" are all supposed to work.  "KAOSTOS" is apparently too heavily modified for TOSBOX to recognize it.

The higher the screen mode you select, the more horsepower your machine needs.  Not only is the VDI working harder, but the emulator has to throw around a lot more data (sometimes more than twelve times as much) between ST memory space and the PC's video memory.  A 486/66 is enough for the ST-compatible modes, but you need something considerably faster if you want to run in 1024x768x16 without spending a lot of time waiting around for redraws.

As with an ST, a graphics accelerator is desirable.  The most popular accelerators (NVDI, Warp 9, Turbo ST) are reported to be compatible with TOSBOX, though Turbo ST is only effective in the ST video modes.  NVDI users report varying success; generally speaking, later versions of NVDI are more compatible with the custom video modes, and 16-color modes tend to be more stable than 4-color modes.

Use an alternate desktop, especially if you use the custom screen modes. If you don't have Neodesk, get Thing, Teradesk, or Ease.

Go to the PC Atari homepage

U.K. TOSBOX Mirror Site

This emulator can be downloaded directly from it's homepage.

NOTE: In order to run this emulator, you must have the emulator itself, and a copy of the ROM's from the original system.  The emulator itself is Freeware.  The ROM's are copyrighted by the programmer or the manufacturer. You are only legally entitled to use ROM files if you own the actual game, or a PCB/ROM Cartridge from the game that you are emulating.

ROM's are not available on Back In Time,
but they can be found on the Internet.