Killer Instinct Dual Board

[luke7110]

Sick! Where's the how-to video?

Well, all you need to know is in this thread, you need to patch the U98 with the @DogP patch and follow the @twistedsymphony's hints for the wiring

Here are some pictures from my install. The acrylic case is the one from Emiliano Arlettaz and I made a simple design to integrate a switch between the bottom plate and the PCB.

 

[luke7110]

Nice, glad it worked out for you! Have you (or anyone) played all the way through KI2 using the hacked ROM yet? Just curious if anyone's confirmed that the hack is bug free... I've personally only played a few rounds.

DogP

Thank you @DogP ! Your work on the project gave me the motivation to do all this !
I haven't got the chance to do an extended play yet, but will do and report if there's a bug. At the moment the only observation I can do is the red screen after boot, right before the intro.

 

[HornheaDD]

Damn this is amazing. I would love go be able to find a KI board out there and do this!

 

[stj]

next mod, use some ttl or a small microcontroller to bankswitch based on button combo's instead of the slide switch

 

[luke7110]

Yeah, next mod then... ! I'll enjoy this one for now

 

[DogP]

At the moment the only observation I can do is the red screen after boot, right before the intro.

Hmm, I never paid much attention... but the red screen flash isn't normal?

next mod, use some ttl or a small microcontroller to bankswitch based on button combo's instead of the slide switch

I mentioned in one of my previous posts - this may not work easily. When I tested this, switching with a warm reset didn't seem to properly switch the hard drive. I didn't track it down... I kinda suspect the controller on the IDE->SD adapter didn't like me switching SD cards on it. So maybe it'd be OK if you used two identical SD cards, or find some way to force the controller to reset... or maybe eliminate that adapter and use two CF cards. But it could be something IDE related on the KI board itself as well. I guess you could add a relay and have the MCU cut power to the board, but that's not a very elegant solution.

DogP

 

[luke7110]

Hmm, I never paid much attention... but the red screen flash isn't normal?

DogP

Given the red color, I just assumed it was an error code reporting the lack of the HD interface, and being bypassed by your hack.
But I checked on mame and it does the same ... so I guess it's the normal behavior !

 

[luke7110]

I'm experiencing a strange behavior with the credit system: when I push the coin button sometimes it doesn't credit at all, sometimes I have to push several times and the credit suddenly increase, sometimes everything is normal.
Could it be related to the dual mod ?

How works the backup system for settings, credits bookkeeping, scores, etc...? Where is this stuff stored? Could it be a data overwrite or conflict related to the dual board setup?

 

[stj]

interesting point, i'm not sure if config is in an eeprom or stored on the drive.

 

[luke7110]

After testing, I confirm the credits bookkeeping and game stats are reset after every reboot, however volume level is saved.
Maybe they aren't stored in the same location, and if the former are saved on the HD, there must be a problem in the chain with either the IDE to SD adaptor, or the 2in1 microSD switcher. I should also check that the "read only" switch on the microSD to SD adaptor wasn't activated by accident
Maybe the latter is saved on a sram in the audio section of the board.

I was thinking, I should dig into mame to understand where are stored the settings, and found they are stored in a dif file, but it doesn't tell me how the data is organized into the file and to which device his content is related to...
Ok, from the mame doc "Hard drive difference files store data that is written back to an emulated hard disk, in order to preserve the original image file. The difference files are created when starting an emulated system with a compressed hard disk image."
So, because after playing KI, the only modified file in the mame directory is kinst.dif, I can say for sure that settings, high scores and credit bookkeeping is stored on the hard drive. It confirms there's a problem writing back to the microSD.

 

[stj]

the ide bus has a reset pin, is it triggered by your reset?

 

[luke7110]

I always power off before changing the game selection switch position, I don't just reset it.

 

[luke7110]

I tested without the 2in1 adaptor, with the IDE to SD only, and the weird credit behavior is still present. But I was wrong about the read only suspicion, it can write to the disk, maybe I was resetting too quickly ? My feeling is that reading from disk is working great, but the other way round there are issues ... it's like the communication is not stable... input are queued and accounted by lots. Same for stats, they're probably saved every x seconds, if the communication toward the disk is unstable the stats are randomly saved.

Maybe I should just put it in freeplay and ignore these issues.

@DogP Didn't you notice any of this in your test setup ? I noticed from your pics you're in freeplay, have you tried without ?

 

[DogP]

I have tested without Free Play, though not extensively... I don't remember any issues like you're referring to, but I'll plug the board in again this weekend and look more carefully.

DogP

 

[stj]

a thought.
if something is stored on the board and the 2 games use different values or memory locations then data from one game may look totally F'd on the other,
*BUT* because the games are related, the checksum location / method may be the same so even though the data is BS the game see's it as good.

my pcb is in a box, does it have an eeprom on it??

 

[luke7110]

I had the same thought but, the upgrade kit is an official mod, and, unless there was stated somewhere not to downgrade the board back, they should have anticipated this scenario. That said, I honestly don't think there's data saved on the board.

 

[mathewbeall]

Thanks @DogP and @luke7110!! I got this all going today - and works like a charm. I still need to get that nice acrylic case for it (trying to find someone to make it for me) and getting the wires all nicely routed - but works exactly as advertised!

Matt

 

[TheDeath]

Pretty cool. Too bad these boards skyrocketed in these years. I can't imagin myself buy one for something like 1000 or more and then work on it to have this

 

[luke7110]

Thanks @DogP and @luke7110!! I got this all going today - and works like a charm. I still need to get that nice acrylic case for it (trying to find someone to make it for me) and getting the wires all nicely routed - but works exactly as advertised!

Matt

Cool !! I'm glad you made it without issues
It takes another huge munch of time and sweat to do a clean job by getting all the wires routed properly and hidden as much as possible
And if ever you get an acrylic case, feel free to print my switch holder (or ask someone to print it for you)

 

[Lemony Vengeance]

So.. um.. I hate to ask, but would it be possible to condense this into a handy how-to for people like me who need easy digestion?