Chui updated DCaSTaway, an Atari ST emulator for Dreamcast other other consoles/handhelds.

Features:

Fullspeed with sound.
Fast and accurated (FAME) Motorola 68000 core by Fox68k.
Hardware scaled resolutions.
Dreamcast SD-Card support for savestates and disk changes.
Supports MSA & ST disks images.
Mouse & Keyboard Dreamcast supported.
Virtual Keyboard with triggers L-R.
X button Map a ST-key using X button under Virtual Keyboard.
Joystick is emulated with digital pad + A,X buttons.
Mouse is emulated with analog pad + Y,B buttons.
Crystalline sound without lag.
SH4 exceptions catched for stability.
Superthrottle mode for speed up intros and loading time.
Save disks changes to VMU.
2 floopy drives emulated.
ZIP support.
Filemanager with subdirectories access.
Complete menu with ‘start’ button: load, frameskip, reset…
2 joysticks emulated.
Under PAL dreamcasts ask 60-50Hz selection.
Multidisk support.
Overscan bottom border render.
Atari ST video 50/60Hz switch support.
Close to 100 % compatibility.
TV filter using OpenGL (not for Dreamcast).

http://chui.dcemu.co.uk/dcastaway.html