https://ares-emu.net/news/ares-v146-released
ares is a multi-system emulator initially developed by the late Near, that continues under the helm of Luke Usher and a small team of contributors. LaserActive support was added by Nemesis (who some may remember as developing what I believe was the first LLE cycle accurate mega drive emulator, Exodus).
LaserActive is basically a laserdisc player with support for additional modules (“PACs”), and two of them were game related – the Sega PAC (plays Mega Drive/MCD games) and the NEC PAC (Plays PC-Engine & PCE-CD games).
You can see the individual PAC below which slots in to the bottom left per above:
These modules also enabled the playing of games that ran off special laserdiscs (for Sega, Mega-LD and for Nec LD-ROM²).
What Nemesis has done thus far is enabled the Sega module specific games (Mega-LD). NEC LD-ROM2 will hopefully come in time (If I understand correctly the really difficult work was already done in getting the Sega side working and can be applied for the NEC side, hopefully that is the case). There’s a good write-up here:
In April 2009, a Sega fan decided to look into emulating the Mega LD, a quirky and little-known hybrid of Genesis and LaserDisc. This week he finished the job.
The journey of Laserdisc preservation in general is an interesting one – a major breakthrough came when people realised they couldn’t actually play any of the content that the BBC had compiled in the mid 80s for its Domesday Project, as one of the efforts to preserve it eventually led to the Domesday Duplicator, which allows the full dumping of a Laserdisc. There’s a video embedded in the ROM article above that goes into more detail on how that works
Aside from the duplicator work, where there was a lot of community effort involved in just getting to the point of people being able to back up Laserdiscs properly, Nemesis had to do a lot of work to add the game specific stuff, which I don’t think anyone else was really looking at. Additionally, Laserdiscs are analogue and the size of the data ends up being ~30GB+ even for single sided disc games, and it’s a lot of effort for each dump. As Nemesis mentions in the ROM article, laserdisc rot is a real issue so it’s great this stuff is getting dumped into a usable format now. Which speaking of which is a new format (.mmi) – the LaserActive was a lot more sophisticated then the laserdisc arcade systems of the 80s (eg Dragon’s Lair) in terms of how it accesses the discs, so it needs a format that supports really quick access to that data.