Joined: Sat Nov 27, 2010 6:50 am Posts: 196 Location: Toronto Canada
For people who don't know much about the super fx chips in snes games there's three different versions
the weakest chip is the mario chip which was only found in starfox
the improved chip was the super fx 1 (gsu 1) found in games like stunt race fx and I think vortex
the best chip was the super fx 2 found in doom and some other random games
Overclocking a starfox on its default mario chip is possible but that chip is garbage and doesn't handle overclocking very well. So I got a friend to solder a starfox 1 eprom to a stunt race fx cart
Getting the overclock to work wasn't simple. Removing the resonator and replacing it with a 2 pin crystal either made the game underclock or match the default speed. Even with a 200 mhz crystal it went at the same speed as the 21 mhz resonator. I ended up cutting the clock trace from the super fx chip that connects to the hex inverter circuit. The mario chip starfox cart doesn't have a hex inverter circuit. I wired up a 25 mhz crystal oscillator directly to the super fx clock pin and it finally worked. Here's the video comparing the original cart to the 25 mhz version
I have 3 versions of starfox 1 a mario chip version, a converted stunt race with the super fx 1, and a converted doom with the super fx 2. As expected the doom based starfox handles overclocking the best. I got that cart playing fine at 32 mhz. Unfortunately at 32 mhz starfox 1 goes so fast it freezes at the end of the stage due to it going faster than the programming expects. The game played start to finish no problem at 25 mhz. Tomorrow I'll buy all the oscillators between 25 and 32 mhz and see just how fast it can go. I installed a precision socket so I can easily swap the oscillator.
starfox is my all time favourite game and i must say that this runs a Heck of a lot better its a bit smoother music sound less morphed and looks like the speed of it makes it more enjoyable
Joined: Sat Nov 27, 2010 6:50 am Posts: 196 Location: Toronto Canada
I love starfox 1 as well that's why I invested a lot of work into this. Anyway I played some of route 3 today it seemed a little slow for my liking so tomorrow I go on the hunt for crystal oscillators of various speeds.
I hope you realize that some SF carts DID come with the newer Super FX chips. I remember some thread on BH a while back with a few people OCing their SF carts.
Joined: Sat Nov 27, 2010 6:50 am Posts: 196 Location: Toronto Canada
Tchay wrote:
Maybe I'm missing something? Both versions looked identical in the video...
trust me the second one's faster. I ordered some faster crystal oscillators on ebay so when those show up hopefully the game can run at those speeds and I can post a faster gameplay vid.
Joined: Sat Nov 27, 2010 6:50 am Posts: 196 Location: Toronto Canada
got some more parts and did some testing. Just as a reminder at 32 mhz on the super fx 2 chip starfox 1 plays but freezes at the end of the first stage. 32 mhz on the super fx 1 chip (stunt race fx chip) the game just randomly freezes all over the place (mostly during the intro).
I wired up a 30 mhz oscillator to my super fx 2 cart and cleared all of route 1 with no issues. However route 2 the game first froze on stage 4....then it kept freezing on stage 2 of route 2. Everytime the game froze I would touch the superfx 2 chip and it wasn't even warm. I speculate that the freezing is caused by the super fx 2 running too fast for the programming. I stuck my 27 mhz oscillator back in and cleared route 2 multiple times with no issues. I've also cleared route 1 at 27 mhz with no issues. Tomorrow I'll test route 3 and the 2 secret stages at 27 mhz.....and training mode. But right now it's looking like 27 mhz is the best speed for starfox 1. I couldn't find any four pin oscillators at 28 or 29 mhz but 27 is still a massive improvement over the default 21.5 mhz.
When you overclock starfox 1 the two things that noticably change are the framerate and the speed of the stage bosses. All the popcorn enemies during the stages I'm sure move faster too but you blow them up so fast you won't really notice the speed increase. Enemies and objects in the stages seem to appear at the same speed as they did with the default clock rate which is good. The faster bosses are completely playable and very fun. And of course the increased framerate is amazing. Once I've confirmed that the cart runs the entire game at 27 mhz I'll make a new video of it in action.
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