MiSTer FPGA Forum

Seeing odd SMS behaviour comparing my console to MiSTer. There may be an issue/request in this, but I'm struggling to understand what is happening if anyone can help.

Something strange going on with Golden Axe Warrior.

My PAL no-mod SMS plays my PAL cartridge with the music at the same speed as the MiSTer set to NTSC. However, the gameplay on MiSTer is faster than my console.
I dumped my SMS cartridge with a Retrode and it matches an "other" one 100%.

In fact, MiSTer won't get past the "SEGA" logo when I load the ROM with "TV System: PAL". However, if I load in "NTSC", then switch to "PAL", the gameplay movement speed matches my PAL console, but the music is too slow.

I've no idea how my SMS is doing this, or if this behaviour exists in other games? I've seen an odd forum post where someone said their PAL SMS had "fast" music, but I can't find any solid data. Most sites claim SMS would run at the slower 50Hz consistently, versus 60Hz. Not Golden Axe Warrior's music.
I've got "60Hz" music, but "50Hz" gameplay on real hardware. Anyone familiar with this?

Switching regions after a game is booted is not always the same as booting in that region. I've seen that even on Mega Drive. You might not have any alternative here though since Mister won't boot in PAL, but it can cause discrepencies.

Try disabling the bios. For me on PAL it won’t go past the Sega logo with bios on, but starts fine with it off. The bios also causes an issue in Psychic World, where stage intros will run slowly. I think it’s doing something different to what an original bios does.

With bios disabled, the music plays at the same pace starting on either PAL or NTSC, but if I switch after booting it speeds up or slows down, so I can have slow music by starting NTSC and switching to PAL, or fast music by starting PAL and switching to NTSC. I’d guess the game is programmed to detect whether the system is PAL or NTSC on booting and pace its music appropriately.

Thank you both. Been AFK experimenting. The disabled BIOS setting will make it launch in PAL. The music, or indeed perhaps all of the PAL SMS running, still seems off and does not match my console.

I have a UK Master System II Power Base (Model 3006-05). I don't think the MiSTer is running at the same speed in PAL mode.
Golden Axe Warrior on MiSTer in PAL mode (BIOS disabled), goes clearly out of sync with my console after a few seconds.

A different test of a common game, Sonic the Hedgehog 2. Booted in PAL MiSTer says it is outputing at 50.2Hz.
I ran the MiSTer in PAL and console at the same time, "Button 1" press to start the game.
As the clock ticked from 9:59 to 10:00, the console was at 9:54 (±1 in game "second" I suppose). Definitely not the same speed.

This may be a connected, or entirely different issue than Golden Axe Warrior given it is not nearly as easy to notice by ear.
As a further test, I ran Space Invaders, noting that ROM is only stated for Europe alone (not say Europe + Brazil). Same difference in my console to MiSTer. MiSTer is running faster than my console.

Maybe my console is at fault here? It is about as old as me. I'd be great if anyone else with a PAL SMS could verify the same difference in speed.

1. Switch to EU region
2. Go into OSD and select "Reset" at the bottom.

That will clear up the potential issue that @FoxbatStargazer mentioned.

I my have this wrong, but I think an NTSC console modded to PAL runs at a slightly different frequency to a PAL console. Maybe the MiSTer set to PAL is running like a modded NTSC console?

Yim wrote: ↑Mon Sep 27, 2021 7:20 am I my have this wrong, but I think an NTSC console modded to PAL runs at a slightly different frequency to a PAL console. Maybe the MiSTer set to PAL is running like a modded NTSC console?

Yeah the MiSTer core is currently only using the NTSC clock of 15x3.5795454Mhz = 53.693175Mhz. The SMS PAL clock is 12x4.43361875=53.203425MHz. The core will need PLL reconfig to switch between the clocks like the NES and SNES cores.

https://www.smspower.org/Development/ClockRate

paulbnl wrote: ↑Mon Sep 27, 2021 10:43 am Yeah the MiSTer core is currently only using the NTSC clock of 15x3.5795454Mhz = 53.693175Mhz. The SMS PAL clock is 12x4.43361875=53.203425MHz. The core will need PLL reconfig to switch between the clocks like the NES and SNES cores.

Just updating this post after some continued communication on the Discord, and filing an issue on GitHub.
There is an SMS test build which corrects the issue. I don't know the specifics of how it was implemented, but it appears to match my console. The fix was stated as "Master clock now is set to correct one separately for NTSC and PAL", which is inline with your comment paulbnl.

I have just in the past hour checked my MegaDrive and it appears to suffer from the same issue. MiSTer running faster in PAL than my console. Interesting that you noted the contrast with NES and SNES cores. I'm curious now if it would appear in anything else, but I'm afraid I've reached the limit of the old consoles I own personally. I've been told there is no PAL system master clock in the genesis core similarly, at least as of this post.

Interesting, playing Sonic on the PAL SMS and MiSTer by a friend (who put thousands of hours on the game), he said the game was slightly slow in some areas. Perhaps a frame slow compared to the real PAL hardware. That's really quite the opposite to the MiSTer running faster!
The SMS core using a SNAC does feel perfect, regarding input lag though!

For me, the Mega Drive (which I know quite well) feels perfect. Especially with the SNAC.

I think these are fabulously well running cores though! Really..

[EDIT: Never mind, I had MiSTer BIOS option enabled by mistake. Still, why is the SMS core BIOS slowing down the game when on a real JP SMS with a BIOS, the title etc run smoothly?]

When running Psychic World SMS, once the intro starts, and I press the button to skip it, the "PSYCHIC" and "WORLD" logos scroll onto the screen from the left & right. On my real SMS (JP, NTSC), these logos scroll onscreen smoothly very quickly (1/4 of a second, perhaps?), but in MiSTer, the logos scroll on screen more slowly and with a bit of stutter.