How to add 100-120Hz for lightboost enabled monitors

By ThulsaDoom

Resident (46)

ThulsaDoom's picture

02-03-2013, 20:26

Hi ! Some of you may already know that new lightboost enabled monitors (120Hz refresh rate with backlight strobing) can do perfect animation without ghosting/blur. They look exaclty as a CRT with this hack:

A problem arises when you have a 50/60Hz source (like MSX). It is a common problem for all upscaling in fps, even consoles make this artifact when playing 30fps games on a 60Hz TV set. If you try to simply double the frame to match monitor refresh, image gets a bit "doubled", in fact appearing like ghosting. It is simple to solve though, just adding a black frame just before the drawn frame solves it without noticeable flickering (at least for 120Hz refresh). I have done it in MAME successfully, it is simpky astonishing to see perfect scrolls with no blurriness, like a CRT. Also, WinUAE have been modified by Toni Wilen to check this and works like a charm. I would like to implement the feature in OpenMSX also, or add it as a feature for future releases. What I should modify in sources to accomplish this?

You can check it working in mame in this post:

Check comments (i am cpharlok if you need a precompiled mame for test it)

Thanks for your help!

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By Manuel

Ascended (18860)

Manuel's picture

03-03-2013, 12:18

I guess the best thing to do is join the openMSX IRC channel and discuss it with us. Most knowledgeable about the video output are wouter and mth.