August 2011 – project sd2snes

Latest prototype PCBs arrived

August 11, 2011 ikari Comments 6 comments

Quick update, the latest prototype PCBs arrived a couple of days ago. Assembly is in progress. This revision reduces audio noise from the DAC. This was a problem with 1CHIP SNESes which introduce much more noise, presumably due to their much steeper signal edges on the bus. The noise disappears when using a “custom chip game” case with the additional grounding prongs. I didn’t want to rely on that though, hence the hardware update. 😉

Here they are. I hope this is the last hardware revision, all those prototype PCBs are getting expensive…

sd2snes Mk.II Rev.E back — sd2snes Mk.II Rev. E, back

1CHIP SNES picture quality – quick comparison

August 1, 2011 ikari Comments 9 comments

I did this a while ago and thought it might be interesting. The 1CHIP SNES (1995~), with S-CPU, S-PPU1 and S-PPU2 united in a single chip (S-CPUN), has vastly improved picture quality over the old versions. Most notably the rising edges of the output signal are much steeper, resulting in sharper dark->bright transitions.
This is not an issue of the video encoder, it looks exactly the same via RGB (save for color balance).
Here are some examples to show the difference.
Sorry the pictures turned out quite big but it’s important not to lose any detail here. 😉
The images below show three frame captures from a “regular” SNES. Roll over them to see the 1CHIP version.