TMS-RGB in a CBS Coleco

[Macross_VF1]

So I got myself some of the new TMS-RGB mod chips intended for any system equipped with a TMS992xA video chip. 

I first installed one in one of my MSX computers and next I did it in my Colecovision. Pics below to prove it because we all know it didn't happen other wise.

Some notes on the install, I first mounted the chip the wrong way around so the length of the wires were measured from that position. This of course meant that when I turned it around the other way, the wires were longer than necessary but I cut them down somewhat and changed the placement of the DIN socket. The second picture shows where I pulled the sound from and picture three shows how I placed the wires inside the case. Finally, I know I'm going to catch some flack for the hole I drilled in the case for the DIN socket but I honestly don't think it's a big deal. 

So how's the picture quality? On an old CRT and an old flatscreen TV (2006) it looks bloody awesome (picture 5), however my current flat screen behave really strangely if I connect to it directly, as if it has trouble locking onto the signal (attached video). Now this isn't much of a problem as I plan to run it through an OSSC first but then I run into what looks like vertical scan lines. Picture six shows them though they are much more noticeable in real life. It's not the worst problem though somewhat irritating. Of note is that I see the same lines on my TMS-RGB modded MSX, and other than sharing the same video chip, they only share that they are both PAL machines and the Scart cable so the cable might very well be the culprit.












 

[Falonn]

Nice work!

 

The ringing in your DK picture is a little disconcerting though:

 

 

I never saw anything like that during development.  I wonder if there are some signal reflections happening somehow with your cabling setup?

 

3 hours ago, Macross_VF1 said:

... I plan to run it through an OSSC first but then I run into what looks like vertical scan lines.

Have you tried adjusting your OSSC's offset controls mentioned in step 10 of the install guide?  I always saw the vertical lines through the OSSC (but not the Framemeister), but I was able to clean them up by tweaking the offsets for each channel.

 

Otherwise, that sync issue is interesting.  I'd imagine newer TVs have started dropping support for ancient resolutions.  It might be getting confused because 240p is very similar to 480i, where it probably doesn't support the former and is trying to force a square peg into a 480i-shaped hole.  Hmm.

 

In any event, that looks like a great install and your DIN adapter still isn't as bad as the 3 or 5 separate holes you see sometimes with composite/component mods.

[Macross_VF1]

6 minutes ago, Falonn said:

Nice work!

 

The ringing in your DK picture is a little disconcerting though:

 

 

I never saw anything like that during development.  I wonder if there are some signal reflections happening somehow with your cabling setup?

 

Have you tried adjusting your OSSC's offset controls mentioned in step 10 of the install guide?  I always saw the vertical lines through the OSSC (but not the Framemeister), but I was able to clean them up by tweaking the offsets for each channel.

 

Otherwise, that sync issue is interesting.  I'd imagine newer TVs have started dropping support for ancient resolutions.  It might be getting confused because 240p is very similar to 480i, where it probably doesn't support the former and is trying to force a square peg into a 480i-shaped hole.  Hmm.

 

In any event, that looks like a great install and your DIN adapter still isn't as bad as the 3 or 5 separate holes you see sometimes with composite/component mods.

Aw crap, that's an old photo from before I attached the shield wire (I think that's what it's called) to the DIN socket . With it attached the ringing is gone.

As for the offset controls I have tried those and experienced no difference, but I did just realize that my OSSC has never been updated. Maybe it's time to do so?

[Falonn]

That's good to hear the shielding fixed it!

[Macross_VF1]

OSSC firmware updated and unfortunately no difference. Next I started fiddling around with the TV settings and I found that the right mix of the 'sharpness', MPEG-artifact reduction' and 'noise reduction' settings on my TV can pretty much eliminate the jailbars. The overall picture quality does become a bit blurrier as a result but it's a compromise I can live with.

I'm usually a bit hesitant to fiddle too much with these kinds of settings as they can introduce strange artifacts and lag but this time it proved to be necessary.

As for the TMS-RGB itself, I can really recommend it to any owners of a system which feature the TMS992xA video chip. While it isn't exactly something a complete novice can install, it doesn't require too much in the way of equipment and skills. And it's hard to beat the price. I was prepared to buy and solder the necessary components myself as I have both the tools and skills to do so but for $30 it's just not worth the effort.