RGB + Synch Amplifier Circuit for Sega SG-1000 II (Mark 2)
This is a Video RGB Hack for the console Sega SG-1000 II (Mark 2).
The Sega 315-5066 Video Chip inside the Sega SG-1000 II (Mark 2) used in the latest version of the console uses two video output formats: NTSC Composite video (converted to RF), and RGB (not connected).
The RGB Video is the stuff from which all other formats are born. Once your RGB is tapped it can be easily converted to Component or S-video, giving stunning output far superior to what the Sega SG-1000 II natively offers (only RF).
There are several caveats, of course. The biggest is the quality of the RGB output – it’s not very bright, and will result in an image without much contrast, so you will probably need to add an amplifier. Even on monitors that display a very good image without the amp you’ll sometimes find the sync signal needs an amp to generate a stable image.
I have used the same RGB/Sync Amplifier used on the PC-Engine, components and the Original schematic are shown below.
Schematic:
Components:
- 4 x 2SC1815 (Transistor)
- 4 x 220 μF 16v (Electrolytic capacitor)
- 4 x 10 μF 16v (Electrolytic capacitor)
- 4 x 75 Ω (Resistor)
- 8 x 10 KΩ (Resistor)
- 1 x 300 Ω (Resistor)
The three photos below show the connection between the RGB Amplifier and the PCB of the Sega SG-1000 II.
Hi, thank you for your information. They were very valuable. I would like to tell that in my case the location of audio and composite were swapped.
I also wanted to ask you a thing. For me the colors are much more “saturated” colors than I’d expect.
With reference t the tms9918a palette , both dark red and light red are very close to what we’d say FF0000, and dark blue looks like 0000FF. For instance, the sky in congo bongo is really blue (and not violetish, as it should be) and the three reds of the first level look pretty similar. In Magical Tree, the face is red instead of pink (light red). Did you experience this problems?
@kamillebidan
Hi, look here:
http://www.nightfallcrew.com/?s=congo+bongo
This is right for me.
On your pcb the Composite and audio are swapped? uhm, you have a detailed photo of your PCB?
Dave.
Hi, I am currently working on a casemod project. I would like to use cases of defunct old retro consoles and put a mainboard in it (frankly I doubt much fill fit in but a small mainboard and a hdd).
I’d love to do this for the Mark II and the Mark III (because I love the design). I already found the dimensions (W x H x D) for the Mark III but I can not find them for the Mark II. Can you help me out and send them to me? Because if it is to small I can totally forget about it (Mark III has enough space).
This would be great!
Thanks much!
Man, your job is amazing I love your page, but…
The sync (composite) and audio cables are swap in my sg1000. I take about two days of work check every ic, caps and regulator to finally get it :D.
Anyway, keep going!. There are a lot more people who are grateful than the people who comment
Thank you!!!!