very cool
it takes all of 2 mins to quickly sign up to their forum so not a huge deal. I just registered and grabbed link etc
*EDIT*
actually i see
John Bennett already gave permission for link and info to be posted elsewhere so here is his post below
Ok, I've not done anything much on this in a while, but folk wanted to have a try of the multiplayer linkup WIP.
So, if you download this link, you should be able to have a go at:
Rave Racer
Ridge Racer2
https://philwip.com/wp-content/uploads/2021/09/Mamejb_1.zipInstall it then get the ROMs for those 2 games.
In the folder you will see some batch files
linkup1_to_2.bat
linkup2_to_1.bat
Run both of these to open 2 MAME instances and open the game twice.
It will run like sh*te (1fps) until both instances are open as there's a comms wait in there I need to improve somehow.
Anyway when both running, go into the service menu (Tab, dip switches) and set the CPU number to 2 in the second player and maybe pick a different car colour). Unset the dip to save it. MAME should have two sets of configuration folders - one for each instance. It might be a pain to do as the keyboard may input to both sides, but you should be able to muddle through.
It should now work with 2 players on one PC. Windows will ask for access rights for MAME - say yes. This is because it uses 'globalcomms' to link the games up, the same way the Sega stuff does.
If you read up on how to use that, you should be able to put one instance on another PC over a LAN. It'll involve editing the addresses in the bat files. I've never tried it.
If you want a play of fullscale, then so linkups1_to2, 2_to_3 and 3_to_1 (as it's 3 instances). I think I set the jumpers right for it to run. It's obviously a technicolour nightmare with bad video ROMs. Needs a beefy PC, but it's now spreading the load over multiple cores, unlike one instance of MAME, so I can run it at 60fps here
3 or more players craps out on RR2 and Rave Racer - too many dropped packets in the chain. I need to think of a sync method, but it's hard when there is no 'master' PCB in the Namco system (all boards are considered equal).
Ignore any other 'supported' games in this mini-build - just things I've been dicking on with. You'll want to turn scanlines down too - not appropriate for VGA games and looks awful.
Anyway, this is NOT any kind of official release and I don't know when I'll get to work on it again, but consider yourselves playtesters if you like.