Atari ST emulator on RTEMS

[mdoering at mucl.de]

Hello!

I am the co-author of an Atari ST emulation project. The primary goal is,
to have a fast virtual machine running the Atari ST TOS operating system.
This all works quite well on base of Linux with the SDL library for input
and output.

A secondary goal is to make this emulator available to the public as an
replacement of the old Atari ST hardware. It runs much faster and could
provide access to new kinds of hardware etc. I thought, it would be a good
idea to bake a linux mini distribution and let run the emulator on top of
it. I always had not been so happy with it, because I want to hide the
native OS to the public as much, as possible. I don't want this overhead.
Couldn't I make a linux kernel module from it? But how then access the
devices and all.

But then I had the idea: Why not compile it directly with a small
executive and boot it directly from floppy or harddisk? Ok, and this is,
why I did subscribe to this list now.

It seems, that RTEMS could fit very fine to my needs. It has a posix
interface, and good support for different kinds of hardware. But still
some questions do remain:

- How could I set a video mode 
- How can I address a framebuffer (1 - 4 bit color at first)
- How can I get scancodes from the keyboard
- How can I boot my image then with lilo???
- Is there a port of SDL for RTEMS?

The fine thing is, that I do not need a filesystem. The on top running OS
does this all for itself. I just need devices. Also I would need a system
timer. Best would be 5 ms (200 Hz), but 100Hz would also be ok. Could
RTEMS provide this?

I did boot the picoTK demo and was impressed, how nice all this was
running. Ok, I do not need this itself. But maybe I could take some code
from it to use the framebuffer?

What do you think... Would RTEMS fit well to my project?

--
Martin Doering