Modding a Dina 2-in-1 Telegames Personal Arcade Colecovision

[fastbilly1]

See when I try that the entire thing snaps in half, or I take a chunk out of my finger. Its funny I can work with glass for years and never cut myself, I tinker with electronics for a few days and I cut (or burn) three of them.

[bacteria]

Easy to burn fingers, not just by solder or soldering iron but also unexpectedly too - yesterday I wired a 7805 backwards to see what happened regards voltage (out of curiousity); after a couple of seconds, removed the battery, gripped the 7805 - it was burning hot! Ouch!

[ApolloBoy]

Just thought I'd bump this as I just got a DINA 2-in-1 today. After being unimpressed with the terrible RF, I decided to take a whirl at modding the thing. What I did for composite video was I first wired up a 460 ohm resistor from pin 36 on the TMS9918 to the shield on the RF modulator, which acted as a ground source. Then I took another wire, soldered it across from pin 36, and then connected it to the RF jack (which had been cut off from the RF output). Works like a charm now, and the video quality isn't all that bad either! The audio has a bit of interference, but otherwise it still sounds clear. Finally I added some heat sinks on both the TMS9918 and Z80 to prevent the system from overheating.

Even though the DINA's a pretty cheaply made console, it's actually pretty awesome once it's been modded! Now I just need to find a way to get ColecoVision controllers working and I'm really in business.

[ApolloBoy]

Just wanted to add something for anyone who wants to try this. When I AV modded my SG-1000 II, which uses most of the same hardware as the DINA, I encountered the same interference problem with the audio. With some help from TmEE on SMS Power, I was able to fix it by adding a 0.001 uF cap between pin 9 of the SN76489 and ground. Since the DINA also uses the same audio chip, this method will also work on that system.

[bacteria]

Did that get rid of the blurred graphics and the rainbow effect out of interest?

Quite a bump to an old thread!

I ended up getting a French SECAM Colecovision, as it is native RGB.

[ApolloBoy]

Did that get rid of the blurred graphics and the rainbow effect out of interest?

Well, the fix I described is just for the audio, it doesn't affect video. I have gotten the rainbow effect with my old DINA and with the SG-1000 II I have now, but that comes with the territory since it's composite video we're talking about here.

You can swap out the TMS9918/TMS9118 with the TMS9928/TMS9128, but you will have to build a clock circuit for the Z80 and PSG. The TMS9918 on the DINA (as well as the SG-1000) supplies the 3.579545 MHz clock signal for those two chips, and if you just do a straight-up swap for the VDP, the system won't boot. Thankfully on the SG-1000 and SG-1000 II, there's actually an unpopulated clock circuit on the motherboard so you just need to add in the components. For the DINA though, you'll have to provide that on a separate board.

[bacteria]

Nothing wrong with composite on any other system, composite can look excellent (N64, etc); however on the Dina, the video output sucks.

[ApolloBoy]

If you really wanted to, you could also install an F18A in the DINA, which will get you VGA output. I plan on getting one for my SG-1000 II and maybe another for my CV.

[bacteria]

Let us know how that goes.

If there was a way to get Colecovision, Intellivision, Atari 7800 modded to RGB (rather than the very expensive and rare French Perital versions), that would be great!