Installation (sous UBUNTU) : http://sdlmame.wallyweek.org/
Why doesn’t the Tab key work anymore?
Most likely you have re-configured the « UI Configure » key, normally Tab, to something else. To restore the default settings, the quickest way is to delete the default.cfg file from the cfg/ subdirectory below the main MAME directory. However this will remove any other general input changes, too.
If you have settings you don’t want to lose, you can also edit default.cfg with any text editor, since the input configuration files are in XML format. Open the default.cfg file and find the line that says
<port type="UI_CONFIGURE">. Delete that line and all the lines down to and including the next
</port> line; this should be five lines. Save the file.