50/60 htz sega genesis mod help

[staylor]

Hello all, Quick question is there any reason to put a 50/60 htz on a sega genesis ntsc. Or is it just for pal consoles? (well i acually did it and all i get is a black and white rolling screen for 50htz lol). So i guess what i need to know is did i do it for nothing. Any help would be appreciated
Thanks!!!

Scott

[H360]

I dont believe there is a point to put the 60 hertz mod on an NTSC system. I did it on my PAL system, and the 60 hertz mod makes Sonic the Hedgehog 2 run in full screen, and at the correct speed. I dont know about the other way around.

[Druid II]

The only point is if you want a system that can run every game natively. However I don't know if its possible to mod US megadrives to 50hz.

[Lum]

I believe the problem is composite becomes ntsc 50 like snes, ps1, n64, saturn...

Still it is a necessary step in the process for pal optimized games to play correct.

[staylor]

thanks for the input. So if i put a pal game in the ntsc console, and switch it to 50htz will it work and not have screen roll?

[Druid II]

Still it is a necessary step in the process for pal optimized games to play correct.

All 3 of them, haha.

thanks for the input. So if i put a pal game in the ntsc console, and switch it to 50htz will it work and not have screen roll?

You said you already put in a 50/60 switch and it's rolling at 50hz. So there's some other problem there.

[Lum]

Screen roll usually means a TV who doesn't understand 50htz. Not much the game or console can do, if that is what's happening.

[Bad_Ad84]

A lot of TV's (probably ALL in the US) will freak the fuck out with NTSC/50.

You can use RGB to bypass that part of the issue. But rolling will be TV not liking 50hz.

[staylor]

Ok thanks everyone. I guess it will just be a novilty item to show my friends lol.

[omp]

You can fix with oscillator for both model 1 & 2. 4pin for model 2. Have done this a few times to a genesis for australian conditions. With this you get either pal50 & pal60 or you can wire it to get pal50 & ntsc60 through your selecting switch. Also try the single switch mod to get europe/usa/japan.

[retro]

You didn't say how you're connecting it to your television. RF and composite will show black and white (I assume s-video, too) as the PAL colour subcarrier frequency is different from NTSC. The rolling is, as stated, your television not accepting the 50Hz properly. Depending how bad it is, you may be able to simply adjust the horizontal sync on the television to get a stable picture. However, you'd have to devise a circuit to deal with the colour information. I seem to recall having one in a Japanese Mega Drive - off the top of my head, it was an oscillator, a transistor, and a couple of resistors.

*EDIT* I just looked in a drawer, and there was the circuit! It's an oscillator, a transistor, a resistor and a capacitor.

Here's how it looks:



The oscillator is 4.433618 MHz (as it's to use on a PAL TV), capacitor is tantalum bead (looks like 3.3uF 6V), resistor is 56k and the transistor is NPN (looks like Motorola LC945P). Obviously, if you're altering it to work on an NTSC television, you'll have to adjust the values accordingly. To start you off, the NTSC subcarrier is 3.579545 MHz.

[staylor]

Cool thanks i seen i think what you are talking about from a site called damomonster.com his tutorials are great! And im connecting the3 sega to my tv through s-video (that i did through his site)
heres the site

http://www.damomonster.com/Mod_Pages/SegaMegaDrive.html

Thanks for all your help im really getting into this modding thing.

Scott