I have recently purchased an OSSC box for use with my Sega Megadrive 2 (PAL) console. This works in LX2 mode but none of the other modes work at all. I have tried the tweaks listed in the first post of the “TIPS & TWEAKS: LX3, LX4, LX5 MODES” thread as well as the tweak suggested later in that thread which apparently works for the Panasonic TX-50EX series – but I could not get anything to work.
Please could you advise how I can troubleshoot this problem?
Only thing I could think of is do something similar to how (I think) optimized modes achieve a 16:9 frame:
try h.samplerate in the 1705-1708 range, h. active 1280, adjust h.backporch as needed.
or h.samplerate 1560, h.active 1280 (iirc this is the same as the “generic 16:9” line3x mode).
If this works it’d result in a horizontally stretched 16:9 image that you’d then need to de-stretch by manually forcing your TV to 4:3 mode.
Edit: actually, I realise I have no idea how line3x mode is generated, checking myself my TV reports 1280 active horizontal while h.samplerate is only 1170, which should be impossible. There must be some internal trickery going on, which makes it harder to guesstimate which samplerates could be suitable to test.
I remember asking the question how exactly samplerates are generated for lx3 in another thread, but it went unanswered (Marqs probably didn’t see it even).