Jan ’13 I made a custom circuit board for the region mod pic, will post pics
may ’10 being updated check back often
Megadrive/Genesis switchless-mod using the pic micro 16f630 to change the consoles country code (JAP/EUR) and also the Region (PAL 50hz/NTSC 60hz) , first of all sebs code(based off his saturn mod as its mod is carried over pretty much to this megadrive model setup -see below why its on a particular model though before starting off ) and also petes site @ mmmonkeys for general how-to’s on anything to do with the wiring of rgb cables the mods themselves etc these are the places to go to and read up first on all this as I used them as reference and its very thorough.
we are modding this model: lC BD M5 PAL (the easy one! of the two motherboards to setup ) which may or may not have the ‘ext’ socket at the back which is fine. The reason we can just pass the saturn pc code /chip wiring to the megadrive model is because the saturn resets to GND signal -the megadrive model we are using also does resett on GND.
Theres another model IC BD M5 PAL VA4 which actually has the reset button going to 5v+ to a chip in order to reset the system the saturn code mod is not setup for this which means we need to add extra components to the mix to invert this signal,like for example in this picture you’d use an npn to invert the GND to 5v+
At the moment the 50 goes to 60 correctly but 60 to 50 causes a reset.. possibly a saturn specific feature but in the megadrive I like to be able to put it from 50 or 60 and back again anytime , without resetting the game.
This ill l have to modify the code and try burning it to the pic again..even without this it plays runs fine the rgb scart is working well(thats another thing it has no audio connectors on it yet thats the last bit to do on that side of things, im going to connect the headphones internally to the back of the casing via some phone sockets to the phono plugs which ill add to the scarts audio-in cables; so no dodgy heaphone cables running from outside of case etc )
But that can be later or go check mmmonkeys site on how to make that model work. fortunately I have both boards and I’m chosing the easy option first !
doing a breadboard version like this first was a useful way to see how it would go in the case and was fairly quick to wire up & test the in situ. since i chopped up the board (roughly admittedly)to what i imagined would be its final max allowable size , now i had my bouadarys of what i could draw in the custom pcb design using the eagle app ; Done a test pcb design & printed it out and made a few test pcbs on a copepr slab which could hold around 10-15 pcbs (using the /laser printer /iron /magazine paper way). Looking quite slick for such a tiny board thing amazed that it works(etching via the iron on method) but havent soldered anything to it yet trying to make the process/quality flawless (using a dremel tool but making these tiny holes is tricky but with a drilldown support rig to attach the dremil too sure helps keeping the hand wandering motion when drilling to a strict minimum .. more to come..