MiSTer FPGA Forum

With the following combination:

- Mega CD 2 V2.00W BIOS
- EU region
- 50.2Hz refresh with vsync_adjust=2

I get very consistent stuttering in the introductory FMV on Syndicate for Mega CD.

I've confirmed the dump matches the hashes on redump.org.

I don't see this with other FMV-heavy games (e.g. intro to Microcosm with US 2.11 BIOS and US region/60Hz), but this is (currently) the only European title I have (I'm going to do more testing with the European release of Microcosm as soon as I have it).

Is this a known problem? Am I the only one seeing it? Does anyone else even care about Mega CD? *laughs*

Upon further testing, I've also noticed that the declared internal resolution for Mega CD PAL appears to be wrong (set to the same as NTSC), so I'm not sure the Mega CD core was fully built for PAL...it looks like it tries to run PAL titles with NTSC framing and internal clocks but PAL refresh.

I went down a similar rabbit hole of switching out bios files, but after looking at some youtube vids and loading up the game in Genesis Plus GX I came to the conclusion that the game probably performed this way on original hardware. At any rate I can't find any footage on youtube of this intro running without said hitching.

rhester72 wrote: ↑Wed Jul 22, 2020 8:05 pm Upon further testing, I've also noticed that the declared internal resolution for Mega CD PAL appears to be wrong (set to the same as NTSC), so I'm not sure the Mega CD core was fully built for PAL...it looks like it tries to run PAL titles with NTSC framing and internal clocks but PAL refresh.

None of the cores I've looked at really are built with PAL in mind. The Genesis core only has one master clock which is based on the NTSC crystal freq.

I don't know how receptive Sorg would be to it but I'd like to go through all the cores and add PAL master clock too so that when "PAL" is selected, correct clock timing is used.

It's especially apparent on the genesis core which is much slower in PAL mode (the screen position looks correct when I change the master clock too).

retrorepair wrote: ↑Wed Nov 04, 2020 11:07 am

rhester72 wrote: ↑Wed Jul 22, 2020 8:05 pm Upon further testing, I've also noticed that the declared internal resolution for Mega CD PAL appears to be wrong (set to the same as NTSC), so I'm not sure the Mega CD core was fully built for PAL...it looks like it tries to run PAL titles with NTSC framing and internal clocks but PAL refresh.

None of the cores I've looked at really are built with PAL in mind. The Genesis core only has one master clock which is based on the NTSC crystal freq.

I don't know how receptive Sorg would be to it but I'd like to go through all the cores and add PAL master clock too so that when "PAL" is selected, correct clock timing is used.

It's especially apparent on the genesis core which is much slower in PAL mode (the screen position looks correct when I change the master clock too).

Isn't the "much slower in PAL mode" effect expected though? Like if I load an NTSC game and switch to PAL, it will reduce the speed because pal is 50~hz and NTSC is 60~hz. PAL games then had to be made with this in mind, or sometimes ports were just running slower which was lazy porting.

However, yeah if the clocks aren't in there I could potentially see that being a problem for something like CRT compatibility. Maybe the CRT compatibility isn't an issue because Ascal handles that on it's own, hrm... I'd like to know what you find out!

I'd expect PAL copies of these games wouldn't have had skippy FMV but I also don't know how much the accurate PAL clock will help. I'll report back later.

I can confirm with the PAL clock, stuff like the "Sega" jingle on Sonic 1 is much lower in pitch and a bit slower, which instantly sounded right to my PAL abused ears.

I've played this game on a real SEGA CD and the videos are full of pauses and stutters. Could this be an issue with the game itself, and not the core?