Thursday, 8 August 2013

60Hz Snes Mod Overkill

Soo.. feeling much <3 for my recently purchased Snes & Everdrive cart - fitted the DSP1 - all good.

But... the 50Hz borders sucked ass & game the region compatibility seemed hit 'n' miss with the revision of Everdrive cart I have (1.3/6?) So decided to venture into mod-ing the sucker.

Ordered a couple of switches to be collected in-store @ Maplin (and picked up a couple of spares, just in case).. rushed home all excited, and..

Argh!!! :'(

The switches had their third pin missing!! What the hell man!?! There's a hole where the pin should be, but no pin! Why? Just don't solder a wire on it FFS!!!

Hah! Lucky I picked up those red ones off the shelf huh ¦) - But WTF? They're spring loaded!!

Bugger - It would have cost me more in tube fare to go back than the switches cost & felling impatient, I had to find a way - so went rummaging through the parts box.. And found this little lot:

This is how a computer programmer make a toggle switch :-{)} using a 20 MIP computer (The Atmel AtTiny85).

I began by performing the physical end of the 60Hz / Region mods, by lifting some surface mount pins & attaching kynar wire to the relevant points:

I then used a larger (Mega0256) Arduino to write a small program that read two push buttons and if held down for about a 10th of a second would toggle one of two output pins that I attached to an RGB Led to test its behavior.

I made the toggle so that it would toggle as soon as the button was held, but wouldn't toggle again until you released the button (and added de-bouncing code to remove glitches).

Once the code worked I plugged the AtTiny85 into a breadboard - wired the SPI pins to the bigger Arduino & uploaded the ArduinoISP sketch to it.

Re-jiggled the pin numbers to match the smaller chips layout & then sent the code via the Arduino - through & into the AtTiny85.

I made the RGB Led light up blue when the power is on.. and the Red & Green lights would toggle with the Red & Green switches.. So Blue by default (PAL @ 60Hz) - Magenta for PAL @ 50Hz (B+R), Cyan (B+G) for 60Hz NTSC & White (R+G+B) for 50Hz NTSC.

Ran the wires attached to the Red & Green Led pins directly to the mod-pins (The red 60Hz wire ran through a 2.2K resistor iirc) - And mounted the Led in place of the power light with some hot-glue:

Soldered the Led resistors directly to the bottom of an 8pin chip socket, and the blue resistor is the 2.2K one feeding the 60Hz mod - all sealed with hot-glue.

(I left the top of the socket un-glued so I could re-program the chip if I need to in future.)

More glue & insulation tape & job done :D

Super pimped ¦) No borders by default - 95% of games run by default!!

Technological overkill? - Naaaaah...

And....... Atmel AtTiny85's are cheaper than a single Maplin's switch! :o)