In SNES

Hi all,

I'm on a mission to build a kind of Tristar adapter for my SNES.

I far as I've read, the SNES CPU is supposed to be 100% backward compatible with the NES. So if the instructions used by the NES can be understood by the SNES, surely it cant be too difficult building a cart adapter?

I've looked around for a SNES Tristar adapter and a Hornby Superdeck but I've not had any luck finding one.

I've got right into my electronics lately so I thought 'why not build one' (besides it would be more fun).

Can anyone point me in the right direction for some info?

Cheers

I don't have information but you certainly have sparked my interest. If you make any headway on information i would love to know about it. If I find anything I'll be sure to send it your way.

"The Super 8 (below) allows NES Games to play on the SNES. Both the Super 8 and the Tristar play the NES Games by actually having a chip that contains the entire NES board. This chip can be extracted and used to make a VERY small handheld NES. With this chip, Kevin Horton built the Portendo, an NES contained within a Sega Nomad. If this interests you, here is the chipset. You need an EXTENSIVE knowledge of electronics to build this. Do not expect any help from Kevin, and accept that this will cost a LOT more than converting a regular nintendo or buying the Game Axe."

So, it uses the NES on a chip.

There is also this FAQ:

Neither provide exact information, but a start.
It seems like info on the "super 8" would be most helpful.

you won't be able to do it using the SNES CPU and just lining up pins... you'd have to contend with the different audio and video processors of the NES and SNES. and to be very specific, the CPU in the SNES is a customized 65c816(added display processor), which is a 16-bit hack of the 6502 CPU, the 'c' designates that it is CMOS based. The NES however uses a Ricoh 2A03 CPU, which is a 6502 with added sound hardware. So they are incompatible.

in terms of pure 6502 ASM being able to run on the 65c816, yes, that would work, but due to the customizations in these specific chips, it won't work.

my understanding is that these adaptors are just a separate console drawing POWer from and sending video to the SNES, I'm certain the POWer could be drawn from the SNES, but I'm unsure about being able to bypass the rest of the circutry and use the SNES video outputs...

but then, you couldnt be able to play SNES Games!

Oh, i understand now. i read through it inserting the punctuation. Cool.