Single Switch Region Mod

[EreWeGo]

Okay, so although I got the single-switch mod working, and I have a MegaDrive to Scart cable...I am curious about the "colour-fix" mod as well. Anyone give me some guides/tips on how I could add the colour-fix mod to my exisiting modded MDII. For my Single-switch mod, I have used an "ON-OFF-ON" switch, (it has 6 poles/connectors, but I only soldered to 3).
I cut the trace to pin 107, wired to the right of the switch, (the Red wire in my pics), then cut the trace for pin 46 and wired from JP3 to the left of the switch, and finally wired from the centre connection of the switch to a ground point on the motherboard. It appears to switch fine to all 3 different modes.

Now, what's the easiest way for me to add the "colour-fix" so I still get colour when in 60Hz mode when using composite/RF? Here is my current MDII, (apologies for picture clarity, shitty camera):

DSCF3551.JPGDSCF3541.JPGDSCF3546.JPGDSCF3548.JPGDSCF3550.JPG

Any help would be appreciated.

[omp]

Hey matey

1/Have a look at the link I sent you to Damomonster and his colour fix.

2/Have a look at my hand sketch

Actually since you have used a on off on switch it may be a bit harder. You may have to wire the oscillator (note you will have to use a 4 pin 4.433619Mhz oscillator) in without switching so you get PAL60 (when you select JPN or USA mode).

In my diagram basically cut where I say to R61 (ignore the switch) and wire straight to there, power is done the same. This should work (haven't tried it though) as it is essentially the same theory as the MD1 colour fix.

Which is this

Please note the above is for MD1 I have just put this up as an example.

Edit, I forgot to mention (i was pissed off about some ebay purchases) that you will need to disable pin 7 and either gnd it or apply +5v to lock the encoder in pal mode. Download the encoder datasheet and check as I am on my way to work.

[EreWeGo]

Thanks for that Omp, I'll have a more thorough read through all the examples and diagrams before I decide what to do. If I decided to peform a mod like your version, where would I find the 3.579545 oscillator? I can find a source for the 4 pin 4.433619MHz oscialltor, but not the other? Where did you get yours from?

[omp]

Hey matey I got them from here http://www.hy-q.com.au/oscillators/std-intro.htm Great people and pretty quick to get back to you as well. I don't see why they wouldn't post to NZ.....

I was going to have a crack at this with the Gen2 I got recently over the weekend, as in using the 4.43Mhz oscillator to lock the frequency into the encoder.

But got stuck into a pile of DSlites to recase/refurb.

[EreWeGo]

Holy crap, nice score there mate!

Thanks for the link, I'll have a look, and when do you get a chance to try the 4.43Mhz oscillator in your Gen2, please let me know how it goes.

[EreWeGo]

Just checked that link omp, they have the 4.433619MHz oscillator, but not the 3.579545 in stock, so might wait to see how your testing goes when you get a chance.

[villahed94]

If your Genesis is an american or japanese one, you don't need the 3.58 mhz signal as it's already done on the MD itself. Just grab it to the switch. It's pin 6 on the 1145/1645/2075.

[omp]

Just checked that link omp, they have the 4.433619MHz oscillator, but not the 3.579545 in stock, so might wait to see how your testing goes when you get a chance.

Best to email champ to be sure. From memory they cost me $5.00 each delivered, I bought 10.

[EreWeGo]

If your Genesis is an american or japanese one, you don't need the 3.58 mhz signal as it's already done on the MD itself. Just grab it to the switch. It's pin 6 on the 1145/1645/2075.

Thanks for the info villahed94. I do have a US Genesis 2, but I'm modding a MegaDrive 2, so was thinking of getting the 3.579545, and trying omp's version of the mod.

@ omp: I did email them, that's when they told me they had no 3.579545 oscillators in stock. I've emailed back and asked if they're getting any more, so I'll let you know.

Any chance you have a close-up picture showing the wiring in your mod of the 3 pos, 2 pole switch? (would be cool to have a "visual" of which wires go where, how they're attached to the switch and oscillator etc).

Anyway, thanks again guys, love this site!

[EreWeGo]

@ omp - bad news I'm afraid, I got an email back regarding stock of the 3.579545 oscillators:

"We will add to our stock holding based on customer orders >250 units,
as we have not had an order for this part in 18 months - I do not
envisage adding to our stock."

Somehow, don't think I'll be ordering more than 250 units!

Ah well, at least they still have the 4.433619MHz oscillators...

[omp]

Sheesh I must of been lucky then.....

Have you checked ebay?

[EreWeGo]

Hey omp, just checked eBay, found this:

http://www.ebay.com/itm/3-579545Mhz-...item2c62eed63f

Does that look suitable? Also, slightly reluctant to buy these if we find that a 4.33MHz can be used on a MegaDrive 2 instead, (if the colour fix works like the MD1 mod), but I suppose they're always handy to have in your electronics kit.

[omp]

Huh made a liar out of myself! That is the seller I bought my 3.57(etc)Mhz oscillators from! Totally forgot that, the only reason why I knew that is when I signed into ebay it told me "you have bought this item, buy another?" Sorry about that (in my defence it was a year ago). Also that is a good price, $20AU (about $25NZ) for 10? Not bad, same as what I paid.

I got the 4.443619Mhz as well as 10.00Mhz (for overclocking) from Hy-Q. I paid $41.80AU for the 4.43's (10 delivered) and $42.35AU for the 10's (10 delivered).

I am hoping that this weekend I can have a look at it. But it will be a rev2.3 Genesis 2, as I don't have another MD2 apart from the one that is already modded. I could re-wire that one I suppose... I can't make any promises as I have 7 week old son that enjoys sleeping for 1.5-2hrs then wakes up for a feed as well as a bit of work for Game Traders to do. Actually I might see what they have laying around, might be able to grab one cheap, that way it will be easier since it will be a closer revision. We'll see.

I haven't seen a rev2.3 in a MD2, maybe they didn't do them? Can anyone confirm what revision the model 2 went up to? Same with model 1 rev VA7 (genesis 1 with shorter board), never seen that in a Mega Drive either?

[EreWeGo]

@ omp - damn, a 7 week old son? It's a wonder you even have time to post on these forums let alone find time for modding stuff! Congrats mate.

So normally, the "standard" colour fix for a MDII uses the 3.57MHz oscillator, and a Genesis 2 would use the 4.443?
If you were are going to try using the MD1 colour fix like you theorise above, then you would use the 4.443 for the MDII and the 3.57 for the Gen2, is that correct?
Also, as I mentioned before, any chance you have a close-up picture showing the wiring in your mod of the 3 pos, 2 pole switch? (would be cool to have a "visual" of which wires go where, how they're attached to the switch and oscillator etc).

[omp]

What I will do is redo the mod and take pics of the switch, I will temporarily use the bigger of the two switches that I use for clarity. I use a smaller on-on-on for md2's and nomads.

The colour fix will be 4.43 on either machine. The reason for this is so you get pal50 and pal60. The tv can't read ntsc50 so using the 3.5 oscillator won't work in a permamently wired situation because of this. The reason mine works is because the oscillator is wired through the switch so when the switch is on USA or JPN it thinks itself a Genesis. When it is on AU (pal) the oscillator I added is disconnected and running on the standard clock. Essentially we are dealing with the video encoder, it doesn't care what console it is in as long as it gets the correct frequency to match.