If you are looking for the actual history of the software version:
MAME itself is open source (mostly BSD-3-Clause), but commercial arcade ROMs remain copyrighted. Do not request, share, or link to copyrighted ROMs. This post is for preservation discussion only. mame 0.78 romset archive
Use or RomVault with a MAME 0.78 .dat file (available from the MAME source code repository or historical dat archives). This will tell you which ROMs are correct for that version. If you are looking for the actual history