va7deo / megasys1_a Goto Github PK

By default, the analog video out Refresh Rate is set to Native, which is incompatible with most PVMs. Setting Refresh Rate to NTSC help descramble the sync. Possibly set Refresh Rate to NTSC be default for improved compatibility out the gate?

When running Soldam (latest version, 230923) the 2nd ADPCM channel is inactive. This can be easily verified by entering the soundtest and comparing the music to arcade captures or the OST rip on VGMrips.net. Sound test 03 (VS Mode music) uses both samplers, and turning off the OPM and ADPCM-0 chips in the OSD, leaving ADPSM-1 to play solo results in silence.

Problem
Sync problem/dropout

Occurs
Always or every time a game switches between screens, such as Rod-Land from Intro > Title screen > Demo > High score > [...]

Core tested
MegaSys1_2023_07_02

Hardware used
· Ultimate MiSTer BliSTer Pro Dual RAM
· Eizo 2456 Monitor @ 1920 x 1200 (video_mode=1920,48,32,80,1200,3,6,26,154000) via HDMI
· AOC G2790VXA Monitor VRR @ 1920 x 1080 (video_mode=8) via HDMI

Other settings
vsync_adjust=2
refresh_min=49
refresh_max=76

Other relevant info
· Core build 2023-05-19 and earlier works - no sync issues. Sync issues occur with or from MegaSys1_2023_07_02
· All other cores work without sync issues on both monitors at different resolutions and refresh rates
· Manually adjusting vsync width in the game can make the problem even worse, i.e. lose sync/signal completely

Anything I can do do test or try out solutions, let me know.

I noticed that on my LG C9 i get no sync for these titles with vsync_adjust=1 or 2. I know that this might be a weird interaction between the LG C9 and the particulars of these arcade machines timing, but for a couple of reasons i suspect there might be an edge case with this cores timing or the misters vsync adjustment:

1. all cores, no matter how strange their refresh rates/resolutions/dynamic-switching,work with the LG9 and vsync_adjust=2. Even the notorious X68000 core works at nativ refresh rates and dynamic switching. All cores with <62hz work at all resolutionso, cores with refreshrates >62hz work with higher than hd resolutions e.g.: video_mode=1920,48,32,112,1200,3,6,32,154000
   This makes this core the only one that does not sync and only works with vsync_adjust=0.

2. Even when the core is set to refresh rate NTSC it does not sync. This is what makes this really strange, as at approx 60hz syncing should be no problem. Even the resolution is not very unique as some other cores use the same. Also Scandoubler FX makes no difference - it will not sync no matter what the settings. Tried at all resolutions, mister.ini at default with only vsync_adjust = 2 and video_mode added. No VRR, no VRR settings in the ini.

3. There were some previous cases where vsync_adjust =2 would produce hdmi streams incompatible with some devices (to tight porches/vblanks/hblanks). Fortunately sorg could fix these in the past. Maybe this is one of those cases.

4. The previous version of the core worked MegaSys1_A_20230519.rbf perfectly with vsync_adjust = 2. The lastest does not. Tested with soldam.

So, this might not be a real bug in the core, but maybe the new timings of the latest core somehow trip the vsync adjustment algorithm. I know that vsync adjust = 2 is stretching the hdmi standard a lot, but maybe this can be easily fixed - maybe even with the old cores timings?

The previous core (that run Saint Dragon) was working fine on my setup.
Vsync = 2
In game mode -> Native NTSC

latest core (that run Iga ninja)
All previous games black screen and sporadically blink the image (iga included)
vsync = 2
In game: any mode (60 or native, NTSC or PAL)

BTW, my LCD screen accept all frequencies from 47Hz to 75Hz. And all other cores are working fine with vsync = 2