V-Liner & Jockey Grand Prix Support

[Moondandy]

I've been meaning to do a small write up on this for awhile, as it's a question that comes up every so often: "What are these Neo Geo games V-Liner & Jockey Grand Prix in the my roms pack and why won't they play in the core?".

Towards the end of the Neo Geo's arcade platform's life, units wound up being repurposed as gambling simulators. Two such games were released: "V-Liner", a slot machine game, and "Jockey Grand Prix", a simulation of betting on horses. Both these carts would play fine on original hardware, but the way they works was a bit different as they continuously ran and never ended. Also once you loaded it up you couldn't swap to another cart if you had multiple plugged into your board.

Here is a video of a dude with a copy of Jockey Grand Prix:
https://www.youtube.com/watch?v=q66-qD5DW-Y

And a short one of V-Liner being played:
https://www.youtube.com/watch?v=GXKHDHXFvpU

There is some further discussion on these two here:
https://www.neo-geo.com/forums/index.ph ... rix.90603/

It seems that the reason these games don't load in the core is because they use a different mapper. There isn't much of any documentation on this that I can find though, I'm not sure if Mame support them (if someone with Mame set up is able to check I'd be interested to know). So in order for the core to support these someone would need to figure out what this Mapper is (it's presumably a simple Mapper) and add it into the core.

update: Issue added to repo:
https://github.com/MiSTer-devel/NeoGeo_ ... issues/176

[Moondandy]

Some additional info from Rysha, here is the code for supporting these two games from (I think) Mame:

Code: Select all

case NEOGEO_JOCKEYGP:
            space.install_read_handler(0x200000, 0x201fff, read16sm_delegate(*m_slots[m_curr_slot], FUNC(neogeo_cart_slot_device::ram_r)));
            space.install_write_handler(0x200000, 0x201fff, write16s_delegate(*m_slots[m_curr_slot], FUNC(neogeo_cart_slot_device::ram_w)));
            break;
        case NEOGEO_VLINER:
            space.install_read_handler(0x200000, 0x201fff, read16sm_delegate(*m_slots[m_curr_slot], FUNC(neogeo_cart_slot_device::ram_r)));
            space.install_write_handler(0x200000, 0x201fff, write16s_delegate(*m_slots[m_curr_slot], FUNC(neogeo_cart_slot_device::ram_w)));
            // custom input handling... install it here for the moment.
            space.install_read_port(0x300000, 0x300001, 0x01ff7e, "DSW");
            space.install_read_port(0x280000, 0x280001, "IN5");
            space.install_read_port(0x2c0000, 0x2c0001, "IN6");
            break;
        }

Add ram at 0x20000 - 0x201FFF and they will work most likely. V-Liner has additional controls however, a slow machine lever and buttons, so those inputs would need to be supported.