The SA1 (also labelled RF5A123) is an enhancement chip for the Super Famicom/Super Nintendo.

It is based on the 65C816, which the Super Famicom's main CPU (the Ricoh 5A22) is also based on. It seems quite likely that Ricoh was the designer and manufacturer of the SA1, but I can't find any information about that.

The chip has a Nintendo logo on it, but that doesn't mean it was designed or manufactured by Nintendo. Is there any information on its origin? Perhaps a die shot showing a logo or name?

  • 2
    Without making useless guesses, it's reasonable to assume that it would be a Ricoh chip "specified" by Nintendo. I say this because I think it's unlikely Nintendo would have had any in-house chip manufacturing facility, and Nintendo already had the license agreement in place. Work on emulating the SA1 core might to be a good place to investigate. Also, this forum post covers the licensing arrangements WDC had with Ricoh/Nintendo. Jan 30 at 19:11
  • I can't find any information about Ricoh actually making their own chips (though they obviously did design them, and from 1988 had a PCB manufacturing facility in Japan) so the actual fabricator was probably a Japanese, Chinese or Taiwanese company. The SNES Central site lists Ricoh as the manufacturer, and states that a lot of the information came from "JAPAN SNES MANIA" (maybe a defunct site, as I couldn't find any other refernces to it?). Feb 1 at 1:12
  • If it was a Japanese site them it was probably called Nihon Super Famicom Mania (日本スーパーファミコンマニア). I can't find any sites with that name either.
    – user
    Feb 1 at 20:48
  • This site has a picture and some information about a Ricoh SA-1 emulator development kit, so I think that's fairly conclusive evidence (hopefully). Feb 1 at 21:42


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