Original video modes over RCA on the Raspberry Pi 3/4

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Vanfanel
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Joined: Mon Sep 16, 2013

Original video modes over RCA on the Raspberry Pi 3/4

Post by Vanfanel »

Hello there,

Today I was thinking... would it be possible to, somehow, get the original video modes used by the games over RCA video connection on the Raspberry Pi?

That way, I could connect the Pi to a CRT TV or an external scaler with CRT effects (OSSC, etc) and the games would look correctly with scanlines+shadowmask, etc.

So, all in all, possible at all?

Thanks!
JonAbbott
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Location: Essex
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Re: Original video modes over RCA on the Raspberry Pi 3/4

Post by JonAbbott »

Possibly, although I’ve no idea how. You’d need to use the non-overlay version of ADFFS so it changes physical screen modes.

If an external HDMI device presented the legacy resolutions via EDID, RISC OS will make use of them. You’re probably into bespoke hardware there though.

Alternatively you’d need to run the RISC OS desktop at the game resolution, disable EDID and the Pi hardware upscaler and use an external HDMI to RGB converter.

Disabling EDID is easy enough (add disable_mode_changes to CMDLINE/TXT), disabling the hardware upscaler is sort of possible in CONFIG/TXT by fixing the resolution although you’d obviously be fixed at that one specific resolution.

Probably easier to just buy an Archimedes.
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