frequency question

[zetastrike]

I never fully understood the whole 50/60 Hz thing until I came here. Retro Gamer was talking about it not too long ago and they made it sound like nintendo and sega never bothered converting their games to the European standard. Does that mean all games released in Europe played like crap on their TVs? If you use the wrong frequency, it plays really slow and has graphical errors, right?

[kool kitty89]

If not optimized it will play ~20% slower, though this will mean less slowdown in general. (further slowdown that is) ANd some games could be made easier by this. (of course for the few PAL optimized games released in the US, the opposite was true)

THe graphical errors or artifacts don't have to do with the frequency, but rather the visible scanlines. NTSC only has effectively 320x224 visible (rest in overscan), while PAL can see the whole 320x240 screen. (depending on your TV, a bit of the sides might get cut off too, as well as maybe having less than 224 vertical lines visible; but this has to do with the way the tube -on CRT's- is configured, and with many it can be altered; the 224 lines is a limitation of NTSC AFIK)

[Elusive]

My knowledge - probably very much over-simplified! - is that American and Japanese TVs used the NTSC standard, refreshing the screen image sixty times per second; European TVs used the PAL standard, which refreshed fifty times per second.

So American Genesis' are producing and sending an image to the TV faster than European Mega Drives, hence why people here talk about PAL slowdown. The game could be exactly the same as the versions released elsewhere in the world, but it'd run differently depending on your console.

Some later games were retimed, meaning that they play at the same speed in a PAL console as a NTSC console. Retro Gamer just farted out 'opinions' from the fine folks at GameFAQs again :roll: I think Comix Zone is a good example of a retimed game, off the top of my head. As for it effecting gameplay - the retimed games are generally from the era when they were locked to a particular region, so you can't really plug it in and turn it on and have it go nuts or whatever. I honestly prefer to play Sonic 1 in PAL - Spring Yard and Star Light sound so smooooth! - but it's really up to the player which setting they prefer :)

Really, with the advent of HD TVs and all sorts of new magic, this timing issue really isn't a problem any more unless you're doing something insane like plugging a 360 into a thirty-year-old TV.

Here's some comparison material, anyway:
<object width="425" height="344"><param name="movie" value="http://www.youtube.com/v/b0llsb77Esc&hl=en&fs=1&"></param><param name="allowFullScreen" value="true"></param><param name="allowscriptaccess" value="always"></param><embed src="http://www.youtube.com/v/b0llsb77Esc&hl=en&fs=1&" type="application/x-shockwave-flash" allowscriptaccess="always" allowfullscreen="true" width="425" height="344"></embed></object>
The PAL screen's squished to fit the Youtube resolution and it's cut off the borders, so it's not strictly accurate! but you get the idea.

[Black_Tiger]

That PAL Sonic looks disgusting. PAL players didn't really have the 8 and 16-bit generation ruined that bad did they? RGB doesn't come close to making up for it.

Were bi-compatible TVs available back in the day? At least modern digital TVs do both. I'd rather play a distorted full speed game that a clear broken game. All the Genesis fans who love to trash SNES slowdown are basically saying that the PAL MD sucks (if this is really how bad it is).

[Ghaleon]

I'm pretty sure there's some confusion here.

To my understanding: when you play a Pal-only game on an NTSC Genesis/Megadrive, you get the slowdown observed in the video--I've done it myself and verified this: to me, it was unplayable. When you play a Pal-only game on a Pal Megadrive, it plays at the same speed as if you were playing an NTSC game on an NTSC system. It's only when you play a game on a system it's not meant to play on do you get the timing issues.

[Elusive]

That PAL Sonic looks disgusting. PAL players didn't really have the 8 and 16-bit generation ruined that bad did they? RGB doesn't come close to making up for it.

Were bi-compatible TVs available back in the day? At least modern digital TVs do both. I'd rather play a distorted full speed game that a clear broken game. All the Genesis fans who love to trash SNES slowdown are basically saying that the PAL MD sucks (if this is really how bad it is).

As I said, the comparison's flawed as the PAL video's all to fuck. The sound's accurate, though. Bi-compatible displays exist, certainly, it's just one of those features you get in some brands over others. The Dreamcast was the first machine to offer you a choice of booting in PAL-50 or PAL-60 modes as by then pretty much all TVs could support 60Hz video.

A RGB-SCART connection is probably the tip-top best connection you can have - it's the only way you can get colour out of a modded Mega Drive.

Ghaleon: nope. Sonic 1 is the exact same data whether it's in a European or Japanese cartridge - but if I boot up my machine in NTSC mode, it runs faster than in PAL mode. You're describing retimed games, where the developers consciously chose to get the exact same speed out of PAL consoles as they did NTSC machines.

[Ghaleon]

Sonic 1 is the exact same data whether it's in a European or Japanese cartridge - but if I boot up my machine in NTSC mode, it runs faster than in PAL mode. You're describing retimed games, where the developers consciously chose to get the exact same speed out of PAL consoles as they did NTSC machines.

Gotcha, I didn't know that the Japanese and European versions of Sonic 1 were identical ROMs--I'd consider that giving Europe the short end of the stick right up the shaft, to mix metaphors. How many non-retimed (read "gimped") versions of games did you guys have to endure?

So instead, I might ought to have said "It's only when you play a game on a system it's not meant optimally-coded to play on do you get the timing issues." ;)

So here's a question: does playing a retimed, PAL-only game on an NTSC console give the exact same amount of slowdown experienced in the opposite case, playing an NTSC-timed game on a PAL system?

[Black_Tiger]

Weren't most NTSC-developed games that were released in PAL territories not optimized?

[kool kitty89]

I'm pretty sure there's some confusion here.

To my understanding: when you play a Pal-only game on an NTSC Genesis/Megadrive, you get the slowdown observed in the video--I've done it myself and verified this: to me, it was unplayable. When you play a Pal-only game on a Pal Megadrive, it plays at the same speed as if you were playing an NTSC game on an NTSC system. It's only when you play a game on a system it's not meant to play on do you get the timing issues.

When you play a PAL optimized game on NTSC it will play ~20 % fast, many codemasters games were like this I beleive, at least on the NES. (Play PAL SMB on an NTSC NES an you'll see the same thing, as it's meant for 50 Hz not 60)

However, while the game plays nominally faster, this higher speed will be more taxing on the processor, thus you will see more slowdown in CPU intensive areas. (this works both ways, games on a PAL console will have less slowdown because of the lower framerate, though will be 20% slower overall if not optimized for PAL)

Playing NTSC Sonic will play slow on PAL 50 Hz, not sure if the actual PAL version was optimized, that would be a bad game not to do so with as speed is a big part of it... (likewise sonic 2 would have less slowdown in PAL, in theory)

[Christuserloeser]

Sonic 1 is the exact same data whether it's in a European or Japanese cartridge

The Japanese version of Sonic 1 actually is slightly more advanced than the PAL/US versions (mostly bugfixes and some minor tweaks to the graphics).


Weren't most NTSC-developed games that were released in PAL territories not optimized?

That is correct. No game released before 1992 was optimized for 50Hz, and from the games released in 1992 the only game would be Thunder Force 4.

EDIT: We had a discussion about this not too long ago: http://www.sega-16.com/forum/showthread.php?t=7190

[Ghaleon]

When you play a PAL optimized game on NTSC it will play ~20 % fast, many codemasters games were like this I beleive, at least on the NES.

Interesting, I've never experienced that, sounds fun! :D But this doesn't explain why the PAL-only version of Sonic 3 I once played on an NTSC Genesis was slower and not faster than a native NTSC copy of the game on the same hardware.


http://www.sega-16.com/forum/showthread.php?t=7190

The cited thread also mentions the Sonic 3 slowdown as such, without explaining what caused it--anyone know?:

Some games that are optimized for PAL HW can have artifacts showing or at extreme cases, major slowdown throughout the game (like Sonic3 if you get past region lock).

[tomaitheous]

It should be noted that, if you have a retimed PAL game (from that of an NTSC game) that it will be lower temporal resolution "steps" than NTSC. NTSC has finer "step" (60 frames VS 50 frames). Most games use a fixed point counter/divider anyway, so it can easily be adapted for a 50hz driver/divider/counter system - but there's still going to be some sacrifice. Even with a retimed game for PAL, I'd take the NTSC version over it 9.5 times out of 10.


60HZ IS THE BEST! SAY IT'S THE BEST! COME ON, SAY IT! YOU HAVE TO SAY IT OR I'LL GET LIMP! SAY IT!!!!!

[Christuserloeser]

The cited thread also mentions the Sonic 3 slowdown as such, without explaining what caused it--anyone know?:

Tiido explains it near the end of page 1:


in the NTSC world, your TV shows poor colors and 240 lines of image at time (not counting invisible lines) at 60 images per socond... in PAL was created so that theres better colors and more definition... so you have 288 lines, but it did not come out of nowhere, since bandwidth could not really have been messed with, they made things work in 50 images per second.... now all (well, a big percentage) game consoles provide some timing methods, and most common is using vertical interrups, which is triggered by either 60 or 50 times per second... so, unless the lower periodicity is taken account, a game that's meant for 60Hz will be slower in 50Hz... however, in 50Hz, the frames are much longer thus the CPU gets more time to do other things and this results in less or no slowdown in games that have it. Also, there's 50% more DMA time (the time you can transfer graphics data really fast)... Not too many games were optimized to take advantage of what a 50Hz system offers... I am working on one such game and its going to be a nightmare for me to get it running decently in 60Hz.

[Elusive]

So here's a question: does playing a retimed, PAL-only game on an NTSC console give the exact same amount of slowdown experienced in the opposite case, playing an NTSC-timed game on a PAL system?

No idea. The retiming for PAL regions thing only really became popular when SEGA started region-locking games, so it's mostly a non-issue.


The Japanese version of Sonic 1 actually is slightly more advanced than the PAL/US versions (mostly bugfixes and some minor tweaks to the graphics).

Perhaps I should have mentioned Sonic 2 for all the nitpickers out there :P

PAL-60 over SCART is the King. All hail the King!

[Ghaleon]

Tiido explains it near the end of page 1:

Well, I've read that multiple times now, once before you cited it and twice since, and I don't see how it explains the fact that Sonic 3 (alone of all PAL-only games, so far as I've seen) reacts in exactly the opposite manner as a typical PAL-only game played on NTSC hardware....maybe I'm being dense, but I dont' see it.

When I read that, I get 3 points out of it only:
1. PAL is 50 Hz but higher resolution and color space than NTSC.
2. the internal timing method of choice in the games is the vertical interrupt, i.e. 50Hz for PAL, 60Hz for NTSC.
3. PAL games have to refresh to the screen 20% less often than NTSC games and therefore tend to stress the system less and have more processor headroom for computational tasks.

These all make perfect sense, and while that would explain why a game set to PAL timings would run faster on NTSC hardware, they don't explain the opposite, atypical case of a PAL game running slower on NTSC hardware (neglecting the atypical case of "slowdown" in this discussion).


No idea. The retiming for PAL regions thing only really became popular when SEGA started region-locking games, so it's mostly a non-issue....PAL-60 over SCART is the King. All hail the King!

Well, looks like I asked the wrong question there anyway, if PAL-only games typically experience a speed up on NTSC hardware.

PAL-60? Meaning PAL color-depth and resolution, but at 60 Hz? Can you get that out of a Megadrive/Genesis?

[tomaitheous]

These all make perfect sense, and while that would explain why a game set to PAL timings would run faster on NTSC hardware, they don't explain the opposite, atypical case of a PAL game running slower on NTSC hardware (neglecting the atypical case of "slowdown" in this discussion).


Just speculation, but it could be that the game is expecting a longer active and vblank period and is timed specifically to this. The simple answer would be; shorten both those aspects (active and vblank part of the frame) and the game could slowdown more depending on situations/circumstances. Depending on how the code is setup (wait_vblank_loop/code), a few cycles could "slowdown" a game. But like I said, that's (reasonable) speculation at this point.

Running slower and "slowdown" are two different things being talked about here.

[Ghaleon]

Just speculation, but it could be that the game is expecting a longer active and vblank period and is timed specifically to this. The simple answer would be; shorten both those aspects (active and vblank part of the frame) and the game could slowdown more depending on situations/circumstances. Depending on how the code is setup (wait_vblank_loop/code), a few cycles could "slowdown" a game. But like I said, that's (reasonable) speculation at this point.

Interesting, thanks for the speculation.


Running slower and "slowdown" are two different things being talked about here.

Right: "slowdown" is what most people call it when the CPU is overloaded and can't accomplish everything it's being asked to do in "real-time," so you experience a temporary slow period, like when Sonic loses 50 rings, and overclocking the 68K generally alleviates or resolves this issue, right? I've yet to try overclocking a Genesis.