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(SOLVED)Mario Kart Arcade GP 2: 99 credits hacked in by default?

winteriscoming

winteriscoming

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Any version of Mario Kart Arcade GP 2 that I've found and load up on the Triforce appears to have 99 credits hacked in by default. I think this was done for emulation purposes or for playing it on the Wii. Anyone know of a version that does not do this? I would prefer to have to manually enter credits.

I was looking over the files and I have 2 different versions with slightly different text in the first few lines when viewing in a hex editor. I can't easily pinpoint anywhere to zero out the credits within a hex editor. The version posted on neo-arcadia has 99 credits.
 
Yeah, I just double-checked the version from neo-arcadia. It starts out with 99/1 credits every time. I even had F-ZERO loaded up prior to loading this, so it wasn't a carry-over left in memory from a previously loaded hacked rom or anything.

The three versions I have found so far are:
GGPE02 - Mario Kart Arcade GP 2.iso (viewing hex shows this one has some different text on the first few lines compared to the other 2, but works the same)
MarioKartGP2.BIN (from neo-arcadia)
MarioKartGP2.GCM (exact same as the BIN per a hex comparison)


For the record: The version of Mario Kart Arcade GP 1 on neo-arcadia seems to be fine. 0 credits at boot.
 
My game start at 0/1. I have to insert coins.
I have a Triforce T3 tested in an upright OR2 cabinet (IO type 1), with a working coin system.
Netboot neo-arcadia MK2 file with transfergame and netboot PIC.
 
Gakman said:
My game start at 0/1. I have to insert coins.
I have a Triforce T3 tested in an upright OR2 cabinet (IO type 1), with a working coin system.
Netboot neo-arcadia MK2 file with transfergame and netboot PIC.
Click to expand...
Can you post the MD5 checksum of your rom? Maybe it got reposted with the 99 credit hack?

I'm using transfergame and a zero key PIC, too.

Edit: The MD5 I get from a recent download of the neo-arcadia rom that loads up with 99 credits for me is:
38E96D3F9080515520075CECD693824B
 
Last edited:
Interesting! Here I am blaming the rom, but it's apparently due to my custom I/O. I have no idea why though. I don't have this happening on any other systems or games.

I plugged the Sega Type 1 I/O back in, cleared memory and loaded up MK2 with 0/1 credits.

My bad for blaming the rom. This will be a fun issue to troubleshoot with my custom I/O.
 
Well it's weird. It's not really managed the way I would have thought. Coin switches are not directly reported to the motherboard. Yes, the I/O increments a variable and reports it to the motherboard, but the motherboard translates that as it sees fit and never sends any commands to decrement it. Some games I'm seeing seem to behave like they're just looking for the variable to increase and treats it like reading the coin switch. Some games cap credits at like 9 total, and the variable can go way higher. Then there's the number of coins the game keeps in RAM that don't correspond to current I/O count (which is generally zero initially since I/Os don't have backup memory).

You can see the behavior of coin switches in JVS test. You can see the count increasing for the given coin slot.

So that's the weird thing here: my I/O defaults to 0 credits so I have no idea where MK2 is getting 99 credits from.
 
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