Retro display solutions (monitors, TVs, CRTs, flatscreens, upscaling, calibration)

Discussion in 'Retro & Arcade' started by elvis, Jul 24, 2018.

  1. OP
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    elvis

    elvis Old school old fool

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    I've been to 2 of the "Tip Shops" here in the greater Brisbane area, and they were both shithouse. Very sad. :(
     
  2. bYrd

    bYrd Member

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    Yes, I've examples from visiting two transfer stations in Melbourne that they don't even enter into letting someone take items due to 1) manual handling/safety and 2) data security :p The best things you can get these days are putting the word out amongst friends and family that you're the nerd who likes old tech.
     
  3. Daft_Munt

    Daft_Munt Member

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    I guess I am lucky in Hobart as the 2 main tip shops have old games (console and PC) for sale. Plus cashies had some retro stuff last time I checked.

    Last batch of consoles they had I grabbed another DC and some MD controllers.
     
  4. OP
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    elvis

    elvis Old school old fool

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    We have a couple of notorious "vacuumers" here in Brisbane that just gobble up everything and sell them at stupidly inflated prices in local markets.

    Our city population is small enough that even just a handful have more or less destroyed second hand availability. Not cool.
     
  5. power

    power Member

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    Australia is also a small market, the UK, US and Japan have much healthier markets.
     
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  6. OP
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    elvis

    elvis Old school old fool

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    True, but Japan has retro gaming tourists (guilty as charged), so costs there are going up too.
     
  7. badmofo

    badmofo Member

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    What hardware scanline generators are you guys using, if any? I bought this one recently and it seems OK, but the individual pots for RGB bother me somewhat - I'm never sure that I have the colour right. Setting them all to the same position doesn't look right, I'm sure of that much.

    https://www.ebay.com.au/itm/VGA-Sca...le-For-Retro-Games-Arcade-Gaming/253978187926

    There seem to be a few options out there but is there one that is considered the gold standard? I'm using this with a retrotink for what it's worth, so I guess I could use either a HDMI one or a VGA one (the one I have currently accepts VGA).
     
  8. OP
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    elvis

    elvis Old school old fool

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    They're extremely simple devices - literally just blanking lines on alternate hsync pulses:
    http://www.mmmonkey.co.uk/scanlines-do-it-yourself/

    Some people reportedly found the extreme difference too sharp when using SLGs on LCD monitors, so it was proposed that the pots were added to do a "partial scanline" similar to how some software scanlines offer gradiated options ("25% scanlines", "50% scanlines", etc).

    Good quality SLGs have a good quality triple-pot with a single dial on them that are even, so it's not too much of a drama. Cheap ones (I bought 2 super cheapies off eBay) have three shit quality pots that (a) barely match and (b) are too hard to eyeball perfectly.

    I removed the pots off mine, and shorted the connections. Measuring the pots out of circuit confirmed they were way off compared to one another, and none of them ever got close to zero ohms (meaning there was always something coming through).

    Easy enough to do, and was still worth buying a $15 SLG instead of spending time doing it myself (even though I bought the ICs to do it myself, I caved because I just can't be stuffed).

    I'll take some photos a bit later of the "mod".
     
  9. OP
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    elvis

    elvis Old school old fool

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    Righto here they are. I bought 2 (because they were cheap, and the postage was about 50% of one unit, so I figured why not).

    Left is obviously my hackish modification (I think I had a cut trace, so one of the lines is soldered to its source further away rather than just across where the pot was). Right an unmodified original.

    slg_top.jpg

    slg_bottom.jpg


    The way it works is the hsync pulse triggers a gate that sends each second (or third in "720p thin" or second and third in "720p thick") RGB line signal to ground, causing the picture to show nothing on screen for that given horizontal line. Put variable resistance in the way, and a fraction of the signal makes it to the screen, resulting in a "darker but not black" scanline.

    Here's a SLG photo I stole off the internets (not mine):
    P1110387.jpg

    Notice on that one how there's three pots there, but with one dial (called a "3 gang potentiometer"). Typically if you spend a bit more (like, not single-digit cents per pot) you can get something where the three pots are a bit more even, and the single dial ensures they're always aligned.

    Here's another shot of multi-ganged pots:

    3-watt-potentiometer-500x500.jpg

    I took my pots out and measured them out of circuit. They're supposed to go from 0 to 500 ohms, and mine measured all over the place (one wouldn't go lower than 8ohm, one wouldn't go higher than 470, top and bottom ranges were all different). In addition, the dial rotates about 200 degrees or so, which means trying to get all three identical by eye is almost impossible because lining them up on the board would yield the wrong result, and getting the colour right on screen was impossible.

    If I wanted do have non-black scanlines (say, I was using these on an LCD), I'd either replace these with measured, matched, permanent resistors (you could add a switch in to turn them on and off as well), or put in a better pot like the one pictured.

    But on a CRT, pure black scanlines are nice, as the CRT bloom from the line above and below doesn't look overly sharp like an LCD, even on something like my super sharp late model PC CRTs.
     
    Last edited: May 8, 2019
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  10. badmofo

    badmofo Member

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    Excellent information thanks elvis - as often happens I stayed up later than I'm able to make sensible decisions and ordered an SLG3000. Not cheap! I'll report back once it arrives.
     
  11. OP
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    elvis

    elvis Old school old fool

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    *Excellent* video that explains a whole lot of things, from how your eyes work and how that's related to how TVs work, and a history on light, luma, colour and CRT display choices.

    So much of this still exists today - YCrCb colour space and chroma subsampling is still with us today - it's in part how H264 and H265 work, and how streaming video services and BluRay are compressed, and how your big expensive OLED works out what the picture looks like before sending it to your screen.

    Carve 20 minutes out of your day to really watch it. If it's all new, you may need to watch it twice to let it really sink in.

     
  12. badmofo

    badmofo Member

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    Well the SLG3000 I'd ordered showed up and I love it - 3X more expensive than the first one but a much better quality device, and the locked RGB pots is awesome. Both the in and out VGA ports are female which is a bit awkward but otherwise it dropped with into my setup and the output is amazing - if I knew how to take a decent pic of a CRT then I would, but I don't so you'll just have to take my word for it :lol:
     
  13. OP
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    elvis

    elvis Old school old fool

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    So far all of my smartphone tests have been a failure, as their cameras were all crap.

    On my list is to try my wife's Google Pixel 3 to see how it goes (the camera on it is fairly impressive). In general though, phones up to a few years ago were all biased towards reflective light sources, not generative light sources (i.e.: sunlight bounces off face, into lens, phone captures selfie). As soon as you capture something like a CRT, the sensor just takes in way too much light and loses its mind.

    SLR cameras were far better, but modern multi-camera, multi-lens phones with better sensors might do a good job.

    Other than that, using something to get you the exact focal length you need away from the screen is key. But only after you find something that can deal with capturing a light source properly.
     
  14. badmofo

    badmofo Member

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    I do have a decent SLR here but I think I need to RTFM - mashing at the buttons works out OK for my hardware shots but CRT is still no dice.
     
  15. OP
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    elvis

    elvis Old school old fool

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    "Back in the day" they would fashion a cardboard funnel kind of thing, small end on the camera, big end on the screen, put that up against the CRT, and take a shot that way. It would have the benefit of both removing all external light sources and reflections, but also keeping a consistent focal length and image stability.

    For a still shot (paused image, etc) you could also do things like use a slower shutter speed with smaller aperture to get in a couple of frames of information to avoid the "half a frame draw" problem hat fast shutter speeds end up with, without having your image suffer terrible light bloom.

    A while back I found an excellent article on it from a video games journalist back in the print-magazine and film-camera days. Sadly I've lost the link. Bummer, as it had a lot of great tips on it for this specific needs.
     
  16. MrMaestro

    MrMaestro Member

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    A JVC "PVM" came up on Gumtree in Melbourne yesterday, and the manufacturing date made me do a double take: July 2009. Not even 10 years old!

    Shame it only has composite and S-Video.
     
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  17. power

    power Member

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    probably RGB modifiable, don't be too dissuaded.

     
  18. bolex17

    bolex17 Member

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    Is that a TM-H150CG? You can buy an expansion card off eBay to add RGB to it :)
    I've got the exact same model

    [​IMG]
    [​IMG]
     
    Last edited: Jun 17, 2019
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  19. OP
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    elvis

    elvis Old school old fool

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    Most broadcast monitors have cards that slot in to add features like RGB or SDI (similar to HDMI but used in broadcast).
     
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  20. power

    power Member

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    good to know, and makes sense.
     

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