Latest version for MorphOS is 0.120 (which i maintain

. But anyway, for speed reasons, on a 68k configuration, you'd better stick to very old versions and keep preciously your old rom sets.
Why? From 0.36 to 0.120, MAME emulation got much more accurate and several abstraction layers were added/complexified, which is practice means MAME is now more than twice as slow as 0.36, which is not what one wants on a 68060 config.
