Tips & Tweaks: Lx3, Lx4, Lx5 modes

[marqs]

Can you elaborate which 288p parameters needed adjustments on older firmwares?

I recall my old VT30 plasma didn’t accept sources with more than 1 line off 525/625 spec (PSX 314×2 = 628) – I guess the same goes for newer Panny plasmas. It’s a bit surpising if some tweaks would fix that, though.

[Trixster]

Hi!

This post shows what needed to be tweaked in 0.76, increasing v active to 300:

PS2 240p RGB doesn't work

[Gummi]

Thanks for the replies everyone.

You are really crushing my dreams here 🙁 My model is the TX-P50GT60Y, I would expect it to be functionally identical to TX-P50GT60B. I think the Y models are only sold in the Nordic countries but I would think they are exactly the same as the UK or rest of Europe models. The manual for my exact model also only lists 750 line compatibility and I couldn’t find any mention of PC modes.

If I can’t get it to work, hopefully I will be ok with just 480p. Would be disappointing though. This TV supposedly has an excellent scaler, for video at least, no idea how good it is for video games. How well does the OSSC 480p output look for you on the GT50 @Trixster?

Is the framemeister always better looking on a TV that doesn’t go above the OSSC’s 240p x2 and 480p passthrough outputs, or can that depend on the TV’s scaler? I know the lag will be better regardless.

@marqs , sad to hear that the high end Panasonic plasmas have a history of being inflexible with input signals. Still, I wonder why it works on BonzoBits’ VT60. I know the GT60 and VT60 use the same chipset/picture processor, dubbed the “Hexa-Processing Engine”, and the TV’s function almost identically, so I was hopeful his adjustments might work for me too. But if his is the US version, which it looks like, then all bets are off. Haven’t managed to find a manual for the TC-P55VT60 that lists how many lines it supports to see how reliable the manual information is.

How can I calculate the lines based on the output (240p or 480p for example)? Or is there a list somewhere that lists the resolution lines for different resolutions?

[Harrumph]

Google didn’t find me any list, but here’s some basic info:

480i/480p has 525 lines, for 240p console manufacturers chose either 262 or 263 lines (since 525/2=262.5).

576i/576p has 625 lines, for 288p they went with 312 or 313 (and apparently 314 according to Marqs above, didn’t know that) (since 625/2=312.5).

These line counts are simply multiplied 2-5 times depending on mode.

So e.g. 262 x3 = 786 >> 750 equals problems for some displays.

I made this reference sheet a while back for a selection of VESA and CEA standards.

[Gummi]

@Harrumph thanks! Much appreciated.
I’ll try to keep my expectations low for what my TV can do, but I’ll definitely be adding it to the TV compatability thread.

[coderkind]

Are there recommended settings people have tried for consoles such as PS2 and Dreamcast (480i and 480p)? I don’t know what settings I should be tweaking to try and get x3 or x4 working with them (I just get a blank screen).

Why is 240p seemingly so painless in comparison to 480i and 480p? Every 240p console I’ve thrown at the OSSC so far has been able to x5 without a problem.

[marqs]

@Trixster: funny thing is that those tweaked vertical parameters are somewhat invalid as I noted in a follow-up post, and I think on older firmwares that would have resulted to DE being active during VSYNC. While you had it working, did the TV report the mode as 576p or 800×600?

@Harrumph: Yes, most home consoles output 262/263 lines for 240p and 312/313 lines for 288p, but there are exceptions, most notable Neo-Geo (264 lines) and PSX (314 lines) as listed here.

@coderkind: Does your display support 240pX4? The signal should be very close to 480iX4 and 480pX2. I guess 1280×960 is not widely supported on TVs, you might have luck tweaking relevant modes to generate 1280×1024 output.

[b0nz0beavis]

@gummi My set is the VT60A for ‘Australia’ afaik.

Also, for anyone who has bothered checking my spreadsheet, unless you have: a compatible display, a lot of patience and a need for the sharpest possible image, the spreadsheet isn’t worth the time 🙂 If you stick to generic modes and just use Harrumph’s trick you will still get a nice crisp and colourful image.

[jonlad]

Hi guys, I’m trying to find a used tv that is as compatible as one can be for the ossc

I’ve checked a 42lh35fd LG tv and it looks pretty compatible but could someone check the specs on this page and see if it’s compatible for all modes for snes\megadrive\neo geo\ps1\ps2?

This has the following PC modes:

640*350
720*400
640*480
800*600
800*600
1024*768
1280*768
1360*768
1280*1024
1600*1200
1920*1080

Should this give me Lx3, Lx4 and Lx5 with snes\megadrive\neo geo\ps1\ps2 systems?

Thanks in advance 🙂

[Harrumph]

Well, one can never be sure, but given the track record of other LG screens, and the amount of compatible PC modes, I’d say it’s pretty likely it will work with most, if not all modes.

[Gummi]

@BonzoBits Thanks! You having a PAL model as it were gives me more hope for my GT60Y. I’m in the October batch and I can’t wait to find out what my TV can do.

[jonlad]

Cool thanks!

What about ps1\ps2 compatibility? Would those modes work well with playstations? Or should I be looking for other modes also?

[Harrumph]

Maybe I should add, PC modes won’t work with 50Hz consoles, so you’d need NTSC or switchable modded consoles for those. On the other hand, the TV you linked obviously supports 720/1080p 50Hz so you might not even need to use PC modes.
Compatibility for specific consoles is impossible to say tbh.

[jonlad]

Would that count with a pal soft modded ps2 with USA NTSC games?

[Harrumph]

Yes, I should have written 50Hz signal, not console. The point is, basically none of the PC modes are 50 Hz, they need 60 Hz input.

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