Starwing / Starfox @28.322MHZ glitches & unknown PCB to overclock...

Excellent!
I overclocked my blob version of Starfox (Mario Chip 1) (EURO PAL) using a 28.322 MHZ oscillator & protoboard.
I also have another version of Starwing / Starfox (EURO PAL) which I have not found any documentation or diagrams of how to overclock it? I was wondering if somebody could point me to the right direction?!





Thanks in advance!

Making it go faster would require a different ram chip and if you want it even faster you'd need to romhack the game.

Drakon wrote:

Making it go faster would require a different ram chip and if you want it even faster you'd need to romhack the game.

Thanks for the info!
So 28.322MHZ oscillator is the max I could use on this blob version of Starwing? So is its speed really halved internally and what is the exact speed its actually running now?
Are those graphics glitches actually caused by the overclock and would a slower (27MHZ) crystal fix this?

About that other Starwing board, I was told that I should remove the L1 and connect the clock there.
But do I also need to cut out any trace like in the other mods and do I connect the clock on the top or the bottom point of the removed L1?
And +5V I connect to leg 8 & Ground to Leg 7 of the 74LS139A chip?

Thanks in advance.

Believe it or not the glitching is most likely caused by the ram chip.  I found the ram chips that come on stunt race fx carts overclock way faster.  I built an overclocked starfox cart converted from a vortex cart which the only difference on the vortex pcb from stunt race fx is the ram chip.  On the vortex cart I had all sorts of interesting glitches once over a certain speed.

The problem with doing this mod is you need to use very specific hardware.  I can't tell you why some hardware performs better than others.  Another limiting factor is the eprom / maskrom type.  The type of eprom can actually double the overclock speed.  The final piece of the puzzle is romhacking the game to turn on / off certain hardware modes of the superfx chip that allow for faster overclocking.

You can fix glitches by slowing the overclock, but with the right hardware and romhacking I got starfox running happily at 55 mhz.

For finding where to wire stuff just try to think logically about it.  To find 5v and ground I just googled the snes cartridge pinout and found solder spots that connect to the 5v and ground pins.  For the clock trace, just try to think about what part of it you want to feed your clock signal into.

OK Thanks for the tips, I'll try it out on that other Starwing board next week when I get another crystal.

For the mean time, I managed to find a 27MHZ ACHL-27.000MHZ-EK 3.3V 4-Pin Square oscillator to try it on my blob version of Starfox instead of the 28MHZ which caused the graphics glitches. but it's at 3.3V, unlike the 28MHZ which is at 5V. So should I use a 220 ohm resistor between the game's PCB 5V point and the 3.3V leg on the oscillator so that it doesn't get fried by the higher voltage?

Thanks in advance

You'll need a voltage divider which is a series resistor + resistor to ground.  I forget what values I used but I got 3.3 v oscillators working this way. Google "voltage divider" to see exactly how to do it right, even better is googling "voltage divider 5v to 3.3v".

OK, Thanks!