As CRT televisions have faded from use, it’s become important for retro gaming enthusiasts to get their hands on one for that authentic experience. Alongside that phenomenon has been a resurgence of some of the hacks we used to do to CRT TV sets back in the day, as [Adrian’s Digital Basement] shows us when he adds an RGB interface to a mid-1990s Sony Trinitron.

Those of us lucky enough to have lived in Europe at the time were used to TVs with SCART sockets by the mid-1990s so no longer needed to plumb in RGB signals, but it appears that Americans were still firmly in the composite age. The TV might have only had a composite input, but this hack depends on many the video processor chips of the era having RGB input pins. If your set has a mains-isolated power supply then these pins can be hooked up with relative ease.

In the case of this little Sony, the RGB lines were used by the integrated on-screen display. He takes us through the process of pulling out these lines and interfacing to them, and comes up with a 9-pin D connector with the same pinout as a Commodore monitor, wired to the chip through a simple RC network and a sync level divider. There’s also a switch that selects RGB or TV mode, driving the OSD blanking pin on the video processor.

We like this hack just as much as we did when we were applying it to late-80s British TV sets, and it’s a great way to make an old TV a lot more useful. You can see it in the video below the break, so get out there and find a late-model CRT TV to try it on while stocks last!

Unsurprisingly, this mod has turned up here a few times in the past.

19 thoughts on “Old TV To RGB

  1. I always wondered if the OSD chip in TVs could be used as a video chip for a game console or computer, assuming they’re capable of a bitmapped display instead of just characters.

    1. Some of them would be OK, but you’re probably going to be better served by the almost ubiquitousTeletext chipsets in late model CRT televisions, especially if it supports and implements FLOF which, as far as I know, never really gained much traction but was rather impressive in the demos I saw of it.

      IIRC gaming was one of the services which were mooted with software bought and delivered OTA, all of this was ‘in development’ in the mid to late 1980s.

    2. My family had a mid 1990 Sony CRT, and in the OSD menu it had a brick game, pretty simple, it would transfer to a separate channel, and was monochrome and was played with the remote. I believe that some of these tvs should still be in the wilds

  2. “Those of us lucky enough to have lived in Europe at the time were used to TVs with SCART sockets” should really read – Those of us who lived in Europe were lucky if SCART sockets on the TV worked. Hateful things that should go down in engineering history as some of the worst connectors ever produced. Still fond memories of tinkering around inside CRT’s

  3. That guy seems pretty popular, but I can’t really stand him. So I end up avoiding his stuff.
    Anybody else have that? Because I’m surprised I don’t hear people say that more often. Surely he annoys lots of people, right?
    It’s a good thing I’m not too into retro, else I would be somewhat disadvantaged.

    1. He’s one is the easiest to listen to and most informative people I’ve seen on YouTube for retro computing. I’ve reviewed quite a few of his videos and used what I’ve learned to fix my first retro motherboards, a 386sx.

    2. I find Adrian very calming and I have learned a lot about the current retrocomputing community from him. As a former pro electronics tech I find his knowledge somewhat lacking in some areas but I don’t find him in any way annoying to listen to. To each his own.

  4. Old TVs (my experience is with US NTSC) are pretty video bandwidth limited thanks to the color subcarrier centered at 3.58 MHz. The circuits and components de-contented wherever possible with the notion of limited bandwidth in mind. The other thing to watch out for is that a lot of old TVs, even solid state units, are hot chassis, and there is usually a bleed resistor from both sides of the power line to the chassis. You might get a pretty good tingle even if the (hopefully) polarized plug is in the socket the correct direction, if wiring ACcis reversed somewhere, rather bad stuff could happen. Trinitron TVs similar to the one shown probably have some of the better CRTs, though you get two horizontal lines on a Trinitron due to the shadow from the tension wires in the tube.

    1. Nah still the power supply caps/mains voltage you should be worried about. I’ve been shocked by a billion CRT anodes and flyback transformers and deflection coils, etc.
      They suck but really won’t hurt you unless you’re messing around in a very, very old TV.

  5. I had a really nice Sony Trinitron set in the 90s I always wanted to mod for RGB input but it was live chassis. I did a lot of research into optical isolation of the video inputs at the time bit never got around to doing it. Finding optocouplers with high enough bandwidth was not easy back then.

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