Conversion problem 64mbits roms on cha256

Hi all!

Seeing this slug 2 patch goodness reminded me i still had some wip conversions to be finished.

I wanted to transfer a cha512 slug 2 to a cha256.
The address space is equivalent since slug 2 uses 4*64mbits rom = 256mbits.

Here is what i did:
-c1 rom on c1 socket
-c3 rom on c5 socket
-c2 rom on c2 socket
-c4 rom on c6 socket
-lift a21 & oe from each rom
-oe c1 socket goes to a21 of c1 and c2 roms
-oe c5 socket goes to a21 of c3 and c4 roms
-pass all socket oes to a 74hct08n (and gate) with the following formulas:
-oe c1 socket*oe c3 socket = oe of c1 and c2 roms
-oe c5 socket *oe c7 socket = oe of c3 and c4 roms
- update jumpers for 8*32mbits

result: garbage on most sprites, background is ok through...

Did I do any logic mistakes?

Thanks

Maybe try using the latch output for the high address.

Thanks for this help! Problem was... Dirty cart slot... Yes... Dirty slot...

I am noob for this conversion thing... I only want to convert Metal Slug 2 MVS to AES (Samurai Shodown 2).

I wanted to transfer a cha512 slug 2 to a cha256, I think... But did not understand your explanation is there a tutorial, picture etc ?

thanks a lot.

retro69 said:

I am noob for this conversion thing... I only want to convert Metal Slug 2 MVS to AES (Samurai Shodown 2).

I wanted to transfer a cha512 slug 2 to a cha256, I think... But did not understand your explanation is there a tutorial, picture etc ?

thanks a lot.

Click to expand...

You came to the right place - here's all you need to know: DON'T DO IT. You'll damage/ruin/kill two games that are no longer in production for an inferior result (a conversion). Especially if you don't know what you're doing: STOP.

It would be wiser to buy a MVStoAES converter (like the MagicKey, which will also give you some UniBios functions!) and keep both games as they are. You will then be able to play MVS games on your AES. Wouldn't that be great? Or, also a very nice option, buy/build a CMVS for even less money.