Interlaced scanlines via Extron RGB interface + SLG3000

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SGGG2
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Interlaced scanlines via Extron RGB interface + SLG3000

Post by SGGG2 »

A VERY neat trick I discovered by accident. Not only can you use an Extron RGB interface to get 240p style progressive scanlines from 480i sources with CRT's, but interlaced scanlines on HD panels as well!

Flickering scanlines do a fantastic job of making low resolution textures and heavily aliased models look more naturalistic in 3D games, emulating the look of 480i content on a CRT monitor. The approach detailed here combines the naturalistic look of interlaced scanline emulation with **TWICE** the detail of VGA.

For comparison, the XRGB-3 only offers interlaced scanlines on field doubled 480i content.

The most obvious use is with fast action games for PS2, although I prefer the look of this trick over native VGA or regular 240p style scanlines with Marvel vs. Capcom 2 on DC.

Required:
1) VGA source
2) Scanline generator - confirmed working; SLG3000, Mini SLG -
3) Extron RGB interface with a 6 BNC output - I used a RGB 210 Rxi

Code: Select all

Signal Chain: VGA > RGB Interface > SLG > Monitor / Scaler
All you have to do connect the H-Sync cable to "S" (Composite Sync) and the SLG will render interlaced scanlines!

Working systems:
1) PS2 - forced VGA resolution via GSMode Selector
2) Native Dreamcast VGA.

Working displays / scalers:
1) Gefen VGA to DVI Scaler Plus
2) Acer computer monitor

Not working:
1) Samsung Plasma via VGA input
2) Optoma HD3000

Enabling SOG changes the color temperature from warm to cool.

As an extra bonus, enabling DDSP or SERR reverts the scanlines to 240p style! This means you can switch between clear VGA, progressive and interlaced style scanlines with ease.

Issues:
1) Occasional Rolling distortion wave / screen tearing (from the bottom up) using the PS2 / Gefen Scaler Plus.
2) "Mode not supported" prompt on the Plasma at times (system boot, some game screen / mode changes, changing Extron DIP switches) which required me to power cycle the Scaler Plus.
3) This trick might not work directly with many TV sets, and may require a computer monitor, Gefen or DVDO scaler.

EDIT: Issues one and two may have been related to a loose connection as they disappeared (for now, anyway) after reseating the connectors.
Last edited by SGGG2 on Thu May 05, 2016 1:47 am, edited 1 time in total.
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SGGG2
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Joined: Thu Dec 31, 2009 1:03 am
Location: East Coast, US

Re: Interlaced scanlines via Extron RGB interface + SLG3000

Post by SGGG2 »

CORRECTION

You need a RGB interface with 6 BNC output. H-Sync (white / gray) gets connected to to "S" (Composite Sync). V-Sync's connected as normal.

Sorry if you couldn't get it working! :oops:
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SGGG2
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Location: East Coast, US

Re: Interlaced scanlines via Extron RGB interface + SLG3000

Post by SGGG2 »

lol, so it turns out the SLG3000 already does this without any additional hardware. Simply set both odd and even scanlines set to "on" or "off". Was this ever noted? The Mini SLG, however, doesn't have this feature and requires the method described.
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Fudoh
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Re: Interlaced scanlines via Extron RGB interface + SLG3000

Post by Fudoh »

I think it was more like an unwanted effect when you have a sync polarity mismatch.
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