Yeah, that’s what I love about 480p.
Yes. We need a 480p t-shirt
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You can configure the OSSC to treat parts that are normally part of the image as front porch / back porch but if you go too far it likely won’t work. The numbers I gave above work for my TV but if I try to change the active portion to exactly 480x272 (or even just horizontally 480) the TV refuses to display an image.
I got the numbers I use for active/backporch from here. I haven’t used an oscilloscope but the objective here is not to sample at a perfect dot clock but to somewhat stretch the image on the wire horizontally by abusing the OSSC’s relationship between sample rate and active area and after some testing I found these numbers work properly with squares on screen being equal in length width+height.
Then you rely on the upsample2x to oversample and overcome any image artifacts introduced by not having a perfect dot clock match, effectively smoothly resampling to a higher res image horizontally.
All I remember was how gorgeous, stunning, and fast F-Zero GX looked with my component cables.
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Ah I see. Makes sense, although starting from a point of pixel-perfect sampling would be nice…
I also realized that the numbers for dot clock I’d been using were likely wrong, which threw off all my other numbers. I’m fairly sure of the timing data in my spreadsheet, but the math based on that timing got thrown off by the wrong dot clock.
I don’t think I can determine what the dot clock is without either taking apart the psp go, or having a 240p test suite that I can pull up a checkerboard using.
Do you know if anyone has determined the exact dot clock?
Personally I try not to worry about exact dot for dot sampling. Treating each scanline as a unit instead does give a softer appearance but the result with light scanlines is very similar to what you get on native 480p displays.
I want a 240p shirt. Seriously, I have the design in my head - just need an artist to make it happen!
Send me a PM
Post what you’d like done and I’m sure some of us can help. I’d be happy to help design something.
FWIW, by testing out the lowest I can push V. active before losing pixels off the bottom of my screen, then doing a bit of math (found at the bottom of this spreadsheet) I was able to increase the picture size when in-game without changing the aspect ratio.
The settings I used are:
- V. active - 344
- H. active - 607
Mine ends up looking better without Upsample2x, but I don’t use scanlines. So to each their own, I guess.
Here’s how it ends up looking:
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I finally remembered to look up info on the panel in my Philips 20PF4121 LCD TV @ 640x480. I had to have the PSU serviced recently and my TV repair guy made a note of the panel part number when he had it open. Some models list the panel number on the label, but not here.
http://www.panelook.com/LC201V02-SDB1_LG%20Display_20.1_LCM_overview_3997.html
The TV is officially retro (sold in 2006) so the contrast and brightness are low compared to today’s panels. But it’s IPS so actually viewing quality and angle is great, with fast response and no ghosting.
Panel Type: a-Si TFT-LCD, LCM
Display Mode: IPS, Normally Black, Transmissive
Pixel Format: 640(RGB)×480 [VGA]
Surface: Antiglare, Hard coating (3H)
Brightness: 450 cd/m²
Contrast Ratio: 800:1
Response Time: 12 ms
Viewing Angle: 89/89/89/89 [178/178]
Display Colors: 16.7M , 72% NTSC
Frequency: 60Hz
IPS from 2006? That’s crazy!
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I know! I dread to think how much this little TV cost new. Edit: ~£325 in 2006, dropping to ~£250 in 2007
I read that IPS dates back to 1998, so I’d be interested to see when early IPS panels could be found in consumer displays?
Judging by the macro photos that I posted earlier, I believe my TV uses the S-IPS generation of the technology - due to the chevron-shaped sub-pixels.
https://www.tftcentral.co.uk/articles/panel_technologies.htm#s-ips
It’s also somewhat frightening (from a buyer’s perspective) to see the variation of specs across the single model of panel that I have (and those are the only ones with visible specs) it’s as though brightness and contrast varied by production run and quality control.
Fascinating stuff!
I’ve been looking into Philips 640x480 LCD TVs and have found the strangest thing…
…they’re still being made and sold!
I’ve seen manuals dated 2019 for the 20PFL4122 (my model number plus one; slightly better specs, nicer looking exterior) in the following regions: Australia, New Zealand, Philippines, Thailand, Middle East, China.
So! Given that the panel in mine has apparently not been manufactured in over 10 years, what panels are these new ones using?
Is there anything about scaling being applied or is it all native?
An eBay spare parts search are getting a hit for this panel for the 20PFL4122. The 800:1 contrast matches the spec and the panel info states it’s an IPS according to the specs here:
http://www.panelook.com/LC201V02-SDB1_LG%20Display_20.1_LCM_overview_3997.html
There’s an S-IPS panel variant too, different brightness/contrast though.
That’s the exact same IPS panel that’s in my 20PF4121. Curious.
How much faith to put into the Discontinued and Mass Production date of 2006? Do they really have enough of these old panels to have been producing TVs using them for 15 years?
Also, I found the service manual for the 20PFL4122/79 and that shows this TN panel with 3ms response time and marginally worse viewing angle CPT CLAA201VA07C Overview - Panelook.com but also discontinued and mass produced in 2006.
TN is annoying because it could perhaps mean it’s a crap shoot as to what panel you get? Maybe.
Interestingly, the European version 20PFL4122/10 has HDMI rather than DVI but has a response time of 25ms. These are old 2008-era items that are no longer produced, according to Philips, but can be picked up second hand quite easily in mainland Europe.
With Philips the number after the slash is called “stroke version” and means a regional variation. Examples (main source):
/00 (All Regions?)
/01
/05 UK & Ireland
/10 Europe (Whole)
/12 Continental Europe (excluding UK & Ireland, including Eastern Europe)
/31 (European country?)
/37 USA & Canada (NAFTA)
/38 Mexico
/51 Russia
/55 Latin America (LATAM)
/58 (European country?)
/60 (Ukraine?)
/61 Korea
/69 Singapore
/75 Australia
/77 Argentina
/78 Brazil
/79 New Zealand
/88
/93 China (APMEA?)
/94 India
/96 Taiwan (APMEA?)
/97
/98 Asia-Pacific (APAC)
So service manuals for the old (~2007) 20PFL4122/?? show panel LC201V02-SDB1
And service manuals for newer/current (~2019) 20PFL4122/79 show panel CLAA201VA07C
Which is encouraging to learn that the old models used IPS and the newer/current models use TN.
The eBay part would be for the older sets.
Panel suppliers
- LPL (LG Philips LCD)
- AUO (AU Optronics)
- CMO (Chi Mei Optoelectronics)
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So I bought a 2007-dated 20PFL4122 from Germany for €25 (shipping another €25). It arrived today and will post my thoughts soon. I used eBay Kleinanzeigen (Classifieds) to buy it.
https://www.philips.co.uk/c-p/20PFL4122_10/flat-tv-with-crystal-clear-iii
@Voltz Just saw I missed your question, will address this in my writeup.
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Tonight I finally realised a years long dream of Pixel Perfect Wii.
So happy I could cry. You know the feeling!
It’s a Frankenstein combination of Wii > HDMI > VGA but it works beautifully. Still testing lag but first test was ~20ms which is fine for me.
Will write more and photos soon.
A little bit of Sega Dreamcast action through the Sega Dreamcast - HKT-8100 connected to the ViewSonic G225f.
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