Problems with "Comical Machine Gun Joe"

[mugenmidget]

It seems like every other SMS/Mark III game I try loads just fine, but the SuperMD plug-in does not recognize Comical Machine Gun Joe.  The dump I have works in KEGA Fusion.  If you do not mind looking at it, Conle, I will send you the ROM in question.  And if anyone else has information that might help the game work, let me know.  The SMS Checker by Omar Cornut says the checksum is bad, and recognizes it as an SMS Japan type.  If I use uCON64 to "fix" the checksum, the ROM is still not recognized by the SuperMD plug-in and won't boot on the NEO Myth.

Let me know if there's anything else I can provide that will assist with this situation.  And thank you for all the help!

[ChillyWilly]

That rom is old enough that it doesn't have the "standard" MS header in it. I'm not sure how to detect a SMS rom without the header.

[Conle]

Yeah , there is no way to detect a rom that does not have a header.I could add it to the MD5 mini-database , but i can't guarantee that the plugin will detect every
dump(unless one provide all releases).

A better solution might be a tool that writes a fixed header to those roms , because if it can't be detected by the plugin , then we will have to do this to the menu
also and it will slow-down things a bit.

 

[Conle]

A better solution might be a tool that writes a fixed header to those roms , because if it can't be detected by the plugin , then we will have to do this to the menu
also and it will slow-down things a bit.

I checked this rom , well , a tool will not work with this , because at offset 0x7ff0 there aren't any available pad-bytes to use , so , the only solution is md5 or some
other crc algorithm or custom header

[ChillyWilly]

I could change the default from unknown MD game to unknown SMS game, but then MD games without a header would fail. What we need is a way for the user to specify the rom type directly. I'll think about it a little.

[Conle]

What we need is a way for the user to specify the rom type directly. I'll think about it a little.

Yeah that sounds better.A special option in...the options menu. Like : "Force runmode = MD/32X/SMS" .

[mugenmidget]

Ah, okay, thanks for the information and quick replies!  For now I replaced what was being detected as the header information in SMS Checker with the header from Back to the Future 2 so I'm able to play it.  Love the sound of the "Force Runmode", it's simply amazing how far the menu and programmer have come thanks to your efforts!

Thanks again for all of your help and work with this awesome device!

[ChillyWilly]

Yeah that sounds better.A special option in...the options menu. Like : "Force runmode = MD/32X/SMS" .

Precisely. Just like we allow you to override the save, just override the run type.

[Conle]

For now I replaced what was being detected as the header information in SMS Checker with the header from Back to the Future 2 so I'm able to play it.

"Be careful" because that tool over-writes the last 16bytes with header info and seems like the game has stuff there.Weird things
might happen during gameplay.If it had enough pad-bytes it would've been safe.


Unless this is already a reserved header using some old structure.No idea 

[mugenmidget]

Haha, yea I wondered if there would be adverse effects, but I'm so bad at the game that I can't get far enough to find out.
 

It seems to play the same compared to the unaltered ROM (loaded through Kega Fusion) in the beginning at least, so I can have some fun with it for the time being.  Thanks again for all the help!

[ChillyWilly]

Okay, I was even smarter (lazier) about the "fix" - now I look for the SMS header, or an extension of ".sms" (case matters). So make sure your old SMS roms have a .sms extension and it works.

The code in the svn repo has been updated to reflect the change... it was just three lines added. 

[Conle]

Nope , you aren't lazy at all , we will pretend that we didn't saw anything
By the way , now you have to add this for the flash browser  because you forgot that only with myth v5 you can load SMS games off SD 

ps --
Maybe we could also get rid of "TMR SEGA" check and just do : (size&0x7fff) == 0x10. It should work i think(as long as there is a 16byte header)

[ChillyWilly]

Whoops! Forgot the flash indeed. 

Here's a fix that takes care of identifying SMS roms in flash. You need to keep the name with .sms or .SMS (the SD card file name now looks for both cases too) on the end.

Only problem - the MD plugin doesn't recognize the file still, so it says it's an unrecognized MD rom and aborts. It acts like it's writing it to the flash, but it's nothing but a menu entry... which does ID correctly now. 

So Conle needs to add this extra checking to the plugin before you can actually use it.

[Conle]

Oook    , my turn now i guess   

[Conle]

Here's a test version of the plugin.

Now,when the header is invalid the plugin checks the extension&follows this logic:

If the extension is ".sms"(all cases supported) then SMS runmode will be picked.
If the extension is ".md/32x/bin/gen/mars" and the size of the rom is > 32Mbit , then the runmode is set to MD32X_32_40Mbit
otherwise to MD32X_1_32Mbit(no save).

For all cases a warning message is displayed so that the user knows that something weird is happening behind the scenes.