Composite output from a Sega MegaDrive

Hi,

I do not have a DIN to RGB/RCA cable for my MegaDrive so I decided to add three RCA connectors to the MegaDrive, two for sound and one for composite (yes I know its just mono sound but in the future I will add stereo sound ).

Anyway, I have soldered a cable from pin 1 from this pic: http://pinouts.ru/Game/sega1_pinout.shtml added to the center of one of the RCA-female connectors. Then I have taken ground from the middle of the 7805 on the heatsink and soldered to the RCA-connector.

But I get no picture at all on the 1084 monitor!

Should be enough to get pic on the CRT by hooking up composite video and ground, yes/no?

 

Maybe try ground from the DIN?

Better yet, since you're on a 1084, go for RGB.

 

Yes, might do that.

 

For the price of the three connectors and phono cable, you could have bought a proper RGB cable :\

Why would you want composhite on a 1984 when it's an RGB monitor?! It makes no sense.

 

On the 1084 CRT, composite is not so bad, it is like real time anti-alizing, not so fuzzy image at all. If I want crystal sharp pixel I could run console on the LCD with RGB.

And the 1084 comes in multiple variants, my does not have a SCART socket on the back, just a 9 pin D-sub, so I would need to make a converter.

I like internal stereo mod also, and I like to mod consoles.

And I already had the phono cable, it was free. The three RCA connectors where 0.5 euro each. I have not yet seen an RGB cable for the MegaDrive for 1.5 euro

I was going to add some switches for overclock, PAL/NTSC, english/japan mode on the back and it was going to look totally badass with RCA connectors on the back besides them.

So in my point of view it makes lots of sense.

 

Making a cable would have meant some wire, a D-sub connector and a DIN connector. You should be able to get them for pretty close to 1.5 Euros! If you consider what buying the phono cable would have cost you, you could certainly make it cheaper!

Trust me, try RGB and you won't go back to composhite ;-)

You like stereo instead of mono.. but what you're doing is the video equivalent of settling for mono!

 

I'm the same ,used to live in a house,all mod cons and the like,but i gave it up and went back to living in the gutter :lol:
:banghead::banghead::banghead:

There's no need for using switches and hacking at the md's casing anymore,do the dirt cheap switchless mod

http://assemblergames.com/forums/showthread.php?t=18586
with 1 74hc74 , 3 1k resistors and 1 RGB LED ,or the pic16f630 method .

 

For the amount of hassle involved I'm surprised people go for switchless mods. I guess the appeal is that you don't have to alter the casing. Can't say I'm that squeamish about altering a Megadrive, really...

 

Same here...people rave about the switchless mod but it's a total bastard to do and there's far more risk of screwing up the motherboard if you slip.

You don't even really need to mess the case up. If you don't use the serial connector or the RF out you can use those for the switch holes.

That said there are so many Mega Drives out there I don't think the day where they're hard to find will come any time soon.

 

Are two more wires really going to make things harder? (as you only need three wire for a switched mod). You would have to be an unskilled monkey with brain damage to damage the Megadrive in installing the switchless mod, put the chip on a bread board, solder the wires in place and cover the back of the breadboard with some cardboard, job done. The Led might be a little harder to do, but it is not that hard.

 

Switch-less may not work for everyone, as some models of the MD1 have the reset to trigger at logic high, not low, hence the clock pin isn't pulled low. The PIC option is a bit more universal, albeit more expensive, since the code can be modified to look for a high instead of low. Also, why an RGB LED? Bi-color work just as well, have three colors, and are cheaper.

 

The pic is still overkill, if the Reset is pulled high instead of low then a nice 74hc14 between the reset pin and the 74hc74 would do the trick. Indeed there is no reason to use a RGB LED although it is nice to have Cyan and Magenta as colours.

 

Doh! Yes, an inverter on the reset line would work just as well.

 

Switchless mods really aren't hard to do at all - and when you consider that you'd be drilling the case etc, are they really that much more effort? However, I still don't like them. I want my console to function as normal, not switch every time I press the damn reset button (or whatever button you choose - some people use start)! In some instances, I don't like that the country auto switch determines what speed I should be running the game at, either!

 

Most of the hassle to my mind is sourcing one or more different logic chips. I have resistors, caps etc lying around but not 74 chips.

 

If you've got a 16F630 PIC and a programmer, you could do a Mmmonkey: http://mmmonkey.co.uk/console/sega/md1-switchless.htm

 

I can make the switchless chips as i have the programmer if needed just post me a big load of chips just pay for the return postage.
must be the pic 16f630 there on ebay cheap.

 

Logic chips are common - you'll get them in Maplin, your local radio parts shop, and the usual sources that I posted a thread about. Even eBay.

I don't call that hassle. If your PS2 laser dies, you have to order another - but the actual replacement is no hassle at all. I call that an easy fix.

 

I guess I wasn't clear, sorry. I meant that if I don't have the in a drawer somewhere I'm disinclined to do the mod, that's all.

 

That does seem a lot more complicated then the 74 logic switch one for no real good reason and does require you to hack your pcb. The cost of the 74 chips is probably cheaper then Pic and 74 chip too.