MAME 0.21 was released on 12 May 1997.
The known contributors for this version are, in first-name alphabetical order:
The known contributions for this version are, in the order specified in the whatsnew:
- Virtu-Al submitted full color support for Amidar and Turtles.
- The colors in Arabian (Atari) were corrected.
- A bug where star backgrounds would slow down when frameskipping was fixed.
- The music tempo in 1942 (set 1) was fixed.
- The color strips in Space Invaders were adjusted slightly.
- Mad Planets no longer crashes with its updated sample set.
- Proper colors were added to Warp Warp (Rock-ola set 1).
- The DIP switches in Elevator Action were corrected.
- Dark Schneider submitted a core for the Motorola 6809 CPU.
- Nicola Salmoria added busy-wait detection to the Zilog Z80 CPU core.
- Volume adjustment was added via the "MasterVolume" configuration parameter.
- When bringing up the F4-based tile viewer, DIP switch, or pause screens, audio output is now suspended.
- The user can now redefine the keys that MAME uses.
- The structure used by game samples was modified slightly.
- First version of MAME to support the Motorola 6809 CPU core.
- First version of MAME to support redefinable controls.
- First version of MAME to support a game with an unknown year.