> > MAMEINFO.DAT > > According to your information, when did Mame get 7z support?
Which part of MAME? The original hacky 7zip support was added in d75dbab0de7da33196f08f0cf7992d906ffbb832 (12 Feb 2012). I did the generalised support for accessing .7z and .zip via the same interface some time in 2016.