OSSC v1.xx series beta firmware

[TigerMan8285]

Does anyone have have a link so I can buy the R36 resistor? I dropped it and lost it.

[Fluffyredlobster]

Bit of an odd one, not sure if anyone has any ideas.

I’ve done the hardware mod and have good continuity between pin 25 of U1 and pin 46 of U2, via the R35 pad (resistor removed).  Firmware flashed to 1.09 and I can get sync on a number of sources, but it seems less stable than than the 0.x firmware and there is some weirdness when auto-scanning inputs for sync.

When I have a source powered on and connected to AV1 (PAL Amiga 600 in this case) it locks to RGBS @ 15.62kHz but every so often it looses sync and the LCD flashes to 254.86kHz(!).  Here’s a video of it: https://www.icloud.com/photos/#/icloudlinks/076GlmCk42d0QExiG-kzXNqRQ/0/

When auto-scanning all inputs after the test pattern, if no input is connected it gets as far as AV3 RGsB, the LCD flashes up an input frequency then the auto-scan gets “stuck” on the AV3 inputs – it doesn’t loop back to AV1.  Each time it loops round to AV3 RGsB it flashes up a frequency momentarily, usually either 11kHz or 21kHz.  Video: https://www.icloud.com/photos/#/icloudlinks/062olIDHPf5zEEsFDn_sG9KKQ/0/

It’s a Kaico 1.6 (I know, I know…. they were in stock when I bought it in 2019) so I’m not sure if that maybe a factor.  Firmware 0.90 is rock solid.  If anyone has any ideas I’d appreciate it!

 

@TigerMan8285 – you need a 330 ohm resistor in 0603 size – you can get them from any electronics site / store.

[manuelink64]

what mod is the better one?

– The 1st one, removing SMD resistor R35 and adding a wire between TVP7002 pin 25 (last on the side) and FPGA-end pad of the removed resistor.

– the 2nd, solder a thin enameled wire between pin 25 of U1 and pin 46 of U2.

– the 3rd, rewire the connections between U1 and U2 on an OSSC 1.6 to match the connections on an OSSC 1.8.

 

I can perform all of them, but the 3rd looks more interesting, because the red led is still working.

[Fluffyredlobster]

@manuelink64 options 1 and 2 are basically the same thing.  Resistor R35’s pad is connected to pin 46 of U2 so both options achieve the same end.  The resistor pad is just easier to solder to than the pin.  I assume if you go straight ot pin 46 you still need to remove the resistor.

Option 3 I haven’t tried myself but Morpheus_79 a couple of pages back has done a really neat job and I’m tempted to give it a try, just note his comments on the pin numbers being incorrect.

A note on my sync stability – I think I have improved the first issue by reworking the soldering.  The second issue (auto-scanning getting stuck on AV3) still happens but isn’t really a big issue.

[Pushky]

The issue of the av3 being stuck also happens to me be it on the v1.6 with mod or v1.8 both on 1.09

[Fluffyredlobster]

Ahh, thanks @Pushky for confirming that – at least I know it’s not something I have broken 🙂

[Pushky]

i should thank you, because it also confirms that i didn’t messed up my mod or messed up my v1.8. but i think when i received my 1.8 i think it was firmware 1.07 it worked perfect, but after updating to 1.09 it started, so i guess i must be something with the firmware.

[Fluffyredlobster]

Interesting point – I tried reverting to 0.90 but did not try going back to 1.08 / 1.07.  I will try that later today and report back.

[Pushky]

yeah 0.90 works fine! but whole point of the mod or the v1.8 is to use the v1.xx branch!

[Fluffyredlobster]

So 1.07 and 1.08 do not get “stuck” on AV3 for me.  I still see an occasional sync signal reported on the LCD for a fraction of a second but it correctly rotates back around to AV1.

I’m pretty confident that between this and Pushky reporting the same issue it’s a firmware issue rather than a (my) soldering issue, so I’ll log an issue on github for it.

edit – issue logged: https://github.com/marqs85/ossc/issues/113

• This reply was modified 4 months ago by Fluffyredlobster.

[Pushky]

After seeing your post and trying it myself i can get behind Fluffyredlobster discoveries, i checked the change log for the firmware, and apparently there was some sync changes to it. so the problem might stem from there.
I sorta reported this issue a page back but also got no response… thought i might be my mod so bought a v1.8 to check. i could always sell my v1.6 but yeah!

• This reply was modified 4 months ago by Pushky.

[xepher573]

I managed to desolder the R35 resistor without damaging the board and the pad however, I’m using world’s worst soldering iron and I can’t really melt my solder to get a wire from where the resistor was to pin 25…

 

If I turn on the OSSC without the R35 resistor but no wire to pin 25 will my board be damaged?

[xepher573]

Update: so I decided to turn it on anyways and it works fine without the R35 resistor but without the wire from it to pin 25. But after the update to firmware 1.09 it can’t get sync with any of my consoles.
So I reverted back to the old firmware. Anyways, I’ll get a better soldering iron and finish the job later.

[xepher573]

Update: I managed to finish the mod and everything’s perfect! except one thing: PS2 @ 480i (through component). Passthrough, line2x/etc…, nothing works. Tried both with default settings and Wobbling pixel’s PS2 config and timings. The OSSC just loses signal constantly and randomly.

I started with firmware 1.09 which resulted in PSP working (through component) but Sega genesis (through SCART) getting no sync (OSSC display was flickering with different frequencies and the tv had no signal). Then I tried firmware 1.10 from this github issue and everything worked (but PS2 @480i like I said).

Thanks @marqs for the hard effort! I plan on buying the OSSC pro once I get a job since I find it to be a better option for me than the retrotink5x and the GBS-C doesn’t fullfill all my needs (plus the retrotink4k is way above my price range).

I also have too many consoles to deal with and I don’t wanna use a component/scart switch.

• This reply was modified 3 months, 2 weeks ago by xepher573.

[marqs]

Firmware version v1.10 is now out and possibly will be final official release as the project soon reaches 10th anniversary. The reported sync drop issue with MSX should be now fixed (verified on one console).

* Added support for Lumacode
* Added HDMI VRR flag option
* Reduced sampling jitter on optimized modes
* Fixed sync drop issue with some sources like MSX
* Fixed auto input detection loop
* High/optimal sampling rate modes added for passthru

[Author]

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