Tristar NES adaptor for SNES

In issue 26 of Super Play magazine from Dec 1994 there's an advert by Fire games accessories of Doncaster UK for a Tri-Star convertor that allows NES games to be played on the SNES.

The ad shows the adaptor (a big bulky white thing) and the box it comes in so it must've been a genuine product. Its got a slot for the NES game (any region) and a slot for a SNES game so I guess it works like a standard SNES region adaptor.

The price they sold it for was £39.99 - probably the same price as an NES at the time!

Has anyone got one and did it/does it work ok?

 

It's unlicensed, uses a nintendo NES on a chip (the same kind used in those cheap chinese TV joystick games they used to sell in malls)

It only uses the SNES for controllers, power and video out. Quality-wise, the colors are usually under/over saturated, sound channels are not always balanced or missing entirely (rare) and they have compatibility issues.

They released a similar product for the N64 soon after - uses a bootleg SNES chipset along with the same Nintendo on a chip.

 

The Tri-Star is also known as the Super-8. Not sure if the Tri-Star 64 had an alternate name. I wanted one back during the N64 days but now that I know it's a shitty bootleg I don't think it's worth the high prices people want for them.

 

I picked one up from Gamestation just over a year ago for £5.

Worked ok, went to ebay not long after.

 

Does the Tri-Star use a single NOAC or does it actually use discrete components like older clone systems do/did?

 

It uses a NOAC. A circular black blob. I have some pictures of the PCB.

Here:
http://www.megaupload.com/?d=PH3WKR2Z

 

You sure that isn't just Tristar and not Tristar 64? Afterall that's a SNES connector going towards the console. The black blob looks like a NOAC to me.

 

Gotta love them acid washed/sanded chips they do on these things.

 

The chip is a straight NOAC, no hidden hardware, the design looks pretty simple:

-There's a register which selects either the BIOS or cartridge (BIOS on reset) and selects the audio/video source (NES or SNES), if the design is smart a register bit also disables the register's decoder.
-BIOS has you choose NES or SNES. In the event SNES is selected, the BIOS is unmapped and the CPU jumps to the reset vector, SNES A/V is selected. In the event NES is selected, the A/V is switched to NES, but the SNES BIOS stays in the background polling the SNES controller which it writes to a register read by the NES controllers.

The chips are almost certainly:
-4021 parallel load shift register (NES controller P1)
-4021 parallel load shift register (NES controller P2)
-4066-like analog multiplexer (switch between NES/SNES A/V)
-GAL16V8 as an address decoder with a few I/O used for the config register
-74XXX 8-bit register or latch (store P1 SNES buttons)
-74XXX 8-bit register or latch (store P2 SNES buttons)

It doesn't get much simpler.

 

Hehe, I may spend a little too much time looking at game circuits. It all does fit together though if you know the parts involved, seems they chose the most direct implementation. I wish it was a Wideboy-like thing with a digital video connection, but it's not, the NES system is isolated from the SNES. Theoretically any console could replace the NOAC, space permitting.

BTW, to those interested in using the Tristar's NOAC, Kevtris determined the pinout: http://www.tripoint.org/kevtris/Projects/portendo/index.html

 

So, basically, you could use your N64 for NES games with these two products?

 

I am wondering if this type of adaptor could be have a RGB output through SNES for NES games ?

 

I really don't think the Tristar outputs RGB even for SNES video since it can't switch that many signals and I'm certain it does not for NES since NOAC don't have RGB output.

 

OK, but where is the vidéo output ? SNES is capable of RGB. Tristar 64 has his own video out or the SNES has a video pass through ?

Too hard to find... Like Playchoice 10.