Saturday, 14 February 2015

RGB modded TV transplanted to my first cabinet!

Scored myself a full day in the shed on Friday before last thanks to the Waitangi Day public holiday here in NZ. My girlfriend had to work (poor thing) and the weather was dreadful in Dunedin. Basically, conditions were ideal for an uninterrupted, guilt-free geek-out!

To set the scene, I scored these two New Zealand flavoured cabs from Trade Me back at the start of December 2014. I paid a measly NZD $25 for both! The owner had planned to restore them but decided to abort the project. The lot didn't include monitors or game boards but it did include control panels, marquees, glass panels and a couple arcade power supplies:

Two gutted Coin Cascade cabinets
So, the mission since then has been to find a some CRTs that would fit the monitor cutouts...

After wasting some time trying to work out why WinModelines wouldn't let me set C-Sync for on my laptop anymore, I decided to try an upgrade to my RGB insertion hack I'd been planning for a while. I wanted to see if I could get the Jungle IC in my TV to accept the composite sync signal directly instead of feeding it in via the RCA video input. The idea was that if I could get sync direct to the video chip, there'd be no need to switch to the AV channel in order to have the RGB signal sync.

RGB and C-Sync direct injection to the video processor IC
Along with the RGB and blanking pins on the Jungle IC, there are pins for an external CVBS sync input and also a voltage controlled AV input switch. After mapping out a place to patch into using my multimeter, I wired up a LM317 voltage regulator to produce a steady 8 volts.

Control voltages and RGB interfacing
After soldering it all up, I flicked the power to the chassis and it worked first pop! Excellent! This means the TV can now function as a dedicated RGB monitor. No need to switch the AV input. This is perfect for cabinet use since you don't have to do anything get the monitor to show RGB. It's just like a real arcade monitor!

Panasonic A48KXR98X tube
Philips chassis mounted in cab
Exton RGB 201 RXi for composite sync and level adjustment
So, how does the image quality of a $5 Philip 20PT138A TV with an RGB hack stack up against a SCART television or arcade monitor? Judge for yourself...

Final Fight title screen
Final Fight in game
After (quickly) hooking up an iPAC (the most expensive part of this project by far) I was finally able to play a game on a real-life cab (woohoo!). Once I replaced the fluorescent tube behind the marquee things really started to nail the vibe...

Dangling iPAC
Try This One!
Of course, there are a hundred things I still need to do before I call the project finished (speakers, dedicated PC, new microswitches, cosmetic clean-up, etc.) but I'm pretty stoked with the result!

Looking forward to mounting a vertical monitor in the other cab... should cover many bases.

12 comments:

  1. Awesome work, Dale. Can't wait for the step by step guide for the RGB insertion hack. Now to try and find a CRT TV with a Jungle IC!

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  2. Hi Cameron. "Jungle IC" is basically slang for "Video Processor". Pretty much all TVs have one. It just depends if there's a handy set of RGB input pins present or not.

    I'll try to get to that write up soon... Documentation takes a lot of work and most of the time I can resist charging ahead with new projects instead of writing up the last! But I do want to put something together... it's just too cool being able to get RGB where there wasn't before. I want to share that info.

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  3. The vertical cab will be a sight to behold. I think the vertical size could be increased slightly otherwise a valiant effort and definitely a warm fuzzy feeling knowing CRT are still used in this day and age. Keep the posts coming, which reminds me I have to do the same :(

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  4. you not like flat panel crts, don't you? lol
    in expectation for the step by step guide too, despite i maybe die electrocuted trying this hehe

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  5. İ watching you has long been time real great working and fantastic :) scarthunter number ONE

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  6. Hello i wacthing long time real great worjing and fantastic paradroid number one ;)

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  7. Hello i wacthing long time real great worjing and fantastic paradroid number

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  8. come back... we miss you. :( dont make us wait one year. *chokes back sob.

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  9. Awesome work! How did you go with the documentation? I would like to do this for my Sony Trinitron and would be happy to review/contribute to any doco you have.

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  10. I'll try to do something soon... documentation always takes an age and I've been spending most of my free time (for the last six months) putting together cabinets. I finally finished putting together a schematic (using DIY Layout Creator) last weekend and will do the write-up after I finish off my next cab (it'll have a vertical CRT along with LS-30 rotary joysticks).

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  11. Nice work. I'm in the planning stage of a similar project when I stumbled upon your efforts. Mine is a Sony Trinitron based around a TDA8375A Jungle I/C. Unfortunately I can't find a chassis schematic, however there are plenty of other sets with this IC, so it's been quite easy to work out how to interface it (same as yours by the looks, 75ohm and 0.1uf cap).
    I was planning to just to snip a couple of the pins and wire directly to the chip. The only potential downside is that it may need to be switched to RGB by I2C but we shall see.

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  12. Yeah, I looked into some I2C stuff last year... was thinking it would be amazing to control the Service Menu settings via a PC interface. I think it's something I'll never find the time to go deep into though. :(

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