exxos's Atari, Amiga & retro forum

There is still one annoying issue with my H5s (got 2xH5C), it doesn't work properly with my Medusa scan doubler.
If I plug it using the SCART cable, it's OK, but if I use an UBESWITCH (Mark VI) or an ST2VGA from Exxos store, I can get a picture to display.
The Medusa display an ever fluctuating value for sync signals but doesn't sync. Moreover, I realized the HSYNC frequency displayed is twice the right value (like 31khz for low res..).
Everything works fine using the same setup with an OSSC instead of a Medusa.

So I tried to have a look tonight, scoping the VGA port and I can't see any obvious fault anywhere.
Here are 2 screenshots, first one from a standard 520 STF which works perfectly fine with the Medusa and second one from the H5.

The 520 STF
The H5
At least the scope shows that the sync values are good.(I triggered on VSYNC and a second time on HSYNC).

Measurement is done on the VGA connector at the output of the UBESWITCH.
Obviously I could use the H5 with a VGA connector directly instead of the DIN13 and use the internal jumper to switch Low/Mono resolution and it might work, and I might try that in the coming days, but it also means drilling the case to access the audio jack :-(
Or I could keep using the OSSC, but I must admit the picture quality of the Medusa is vastly superior to what I got after hours of tuning all the parameters of the OSSC.

Don't know anything about Medusa , think Lothrek makes them ? You might have to contact him about it.

It probably would be better using the VGA port on the H5 directly. Also the video DAC does (IIRC) have some jumpers for slightly different modes for stuff you could try..

Yes, the Medusa is from Lotharek. What firmware is installed? 1.0.22 is the last one.
http://medusa-sc.org/firmware/

I need to upgrade firmware, you’re right. When I ran into issues with the Medusa a few weeks ago,I downgraded and I’m now on an old firmware (1.0.18). I will update it and test again. I think the issue is very borderline, today I found in my drawer an ST2VGA made by @logronoide and using it, the Medusa has no problem :dizzy:
But because I’m very unlucky, this ST2VGA was in a drawer for a a good reason, there is a sound issue, you can barely hear anything.
I guess some more troubleshooting tomorrow.

olivier.jan wrote: 18 Apr 2026 18:55 I need to upgrade firmware, you’re right. When I ran into issues with the Medusa a few weeks ago,I downgraded and I’m now on an old firmware (1.0.18). I will update it and test again. I think the issue is very borderline, today I found in my drawer an ST2VGA made by @logronoide and using it, the Medusa has no problem :dizzy:
But because I’m very unlucky, this ST2VGA was in a drawer for a a good reason, there is a sound issue, you can barely hear anything.
I guess some more troubleshooting tomorrow.

I'm looking forward to it – and good luck!

So I updated the Medusa firmware to the latest version and still the same issue. 2 ST2VGA out of 3 can’t be synced while they work fine with OSSC.
Concerning the 3rd one which is working with Medusa, the sound is so low that it’s unusable. I checked continuity, resistance, etc on the audio connection compared to the other ones, and the only difference is the plug is inverted on the 3.5 jack: tip is ground and the 2 others are audio, while on the other ST2VGA, tip and middle are audio and large connector is ground. I will try to invert that by desoldering the smt connector, cut the traces and bodge connect it the other way round.

Spent some time with my son fixing this old Quickshot Arcade stick.
Just a broken connection within the main cable but it took some time to find where.
Now enjoying a nice Bruce Lee time in two players mode.

olivier.jan wrote: 01 May 2026 15:33 Spent some time with my son fixing this old Quickshot Arcade stick.
Just a broken connection within the main cable but it took some time to find where.
Now enjoying a nice Bruce Lee time in two players mode. IMG_2854.jpeg

Well done.

That reminds me that I also have to fix my Quickshot...

I like these joysticks. I disconnected the 2 player cable because it got in the way and it's not like you can play both at the same time.

@HigashiJun this is what I use with my X68000's because it has MSX mode on the switch.

Amiga I use a joystick because that is what I used back in the day, but what with the X68000 and its arcade conversions, this arcade stick feels better suited.

@Higgy

I use the Quickshot with my ATARIs.

I have this one for my X68: