SMS VDP data transfer bandwidth duing vblank

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tomaitheous
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Re: SMS VDP data transfer bandwidth duing vblank

Post by tomaitheous »

Effects that the NES can do as well. MetalStorm is an exercise in dynamic tile basturmation, and later NES games like Vice: Project Doom, Bucky O'Hare, and The Curse of Possum Hollow show off hsync scrolls. The one thing PCE has over NES and SMS in this sense is more sprite overdraw.
In relation to parallax effects? I would say that it goes a little bit farther than that. The PCE has a proper X/Y/BG/Spr reg control system for scanlines effect - per scanline. All the regs are buffered, and don't have to worry about precise timing in order to get updates done per scanline. The SMS can't even change the Y scroll mid scanline. The PCE can do all of it (including changing the screen res, and bit depth mode per scanline), and without timing issues - and the processing power to back it up (effectively 4x times those systems). PCE has unlimited bandwidth to write to VRAM during active display. Whatever dynamic tile setup the NES and SMS can do, the PCE can take it much further. It can even do hardware assisted transparency (abusing planar tile format) as independent scroll layer (I have demos for this).

NES can swap out a whole block of memory, but the dynamic tile edges are going to be severely limit (to squares), on top of the color limitations of dynamic tiles showing behind objects (Gradius 2, Parodius on PCE). On the PCE, you write dynamic tile data to bit planes 0 and 1, for edges, so that the fake BG layer scrolls behind none tile segment seams (Ninja Spirit does this for the tree leaves in the second stage). There's quite a bit of unexplored area of what you can do on the PCE in relation to dynamic tiles that you can't do on the SMS or NES. Some of it has to do with more cpu resource available, and some of it has to do with the expended subpalettes of the BG layer.
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tokumaru
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Re: SMS VDP data transfer bandwidth duing vblank

Post by tokumaru »

tomaitheous wrote:Lol! If you actually played those games, then you wouldn't think so.
Probably not, but those static screens do invoke a Master System feeling from me.
You know that Monster's Lair is also on the Genesis
Yeah, and it doesn't look particularly good there either.
Tatsujin looks SMS-ish???
Not all the time.
This game looks sms-ish to you? http://www.youtube.com/watch?v=LAjr4sJrhrs
At times, yes.
You'd have to take the time to play through the library yourself (hucard and CD), and not spend just a few minutes with each game.
I'm sure it's a good console, but to be honest, knowing that it would cost me a fortune to acquire the actual hardware kinda puts me off. I know I can just emulate, but I can't help wanting to buy the actual systems I like.
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Re: SMS VDP data transfer bandwidth duing vblank

Post by tomaitheous »

Probably not, but those static screens do invoke a Master System feeling from me.
Highly unrepresentative of the system though. You could cherry pic graphics on the Megadrive and say the samething. It would be just as inaccurate or unrepresentative.
I'm sure it's a good console..
That's irrelevant to me, because that's subjective. I don't care if someone dislikes the PCE library or whatever aesthetics about it hardware. I dislike 95% of the games on the SMS because they just don't click with me (I own the real system) - it's 8bit like the NES, but it lacks the charm and the play style of the NES games IMO. But my point, is that PCE games don't look like SMS games. If anything it would be the other way around - later gen SMS games approached PCE and MD in some graphic departments. But as tepples pointed out about pics being deceiving relative to graphics and parallax (PCE), the same is true for SMS coming closer to the next gen era systems; SMS games look better in stills than they do in action and in gameplay.
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Banshaku
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Re: SMS VDP data transfer bandwidth duing vblank

Post by Banshaku »

@Tokumaru
My first console as a kid was a sms and played a lot with it. I was able to get a turbograph later as an adult and there is a lot of interesting games to try. Emulation is more than enough if you want to try.

Compared to sms pce could do bigger objects on screen and usually game felt more smooth. Some were slower like bloody wolf but the arcade was similar in speed so I didn't mind much (it's a good game by the way). There is a lot of cd game with great music like lord of thunder and many shooter too like megadrive.

You should give it a try. I can make a list of interesting games to try someday, even though I'm not as knowledgeable about it compared to nes.

Maybe we should go back to sms vdp subject, there was some interesting information coming out and I would like to learn more about it too.
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Re: SMS VDP data transfer bandwidth duing vblank

Post by tokumaru »

Banshaku wrote:Emulation is more than enough if you want to try.
I know, but in addition to not having much time these days for new games, I fear that I might like them enough that I'll want to buy the real thing, which I don't currently have the money or space for.
Compared to sms pce could do bigger objects on screen and usually game felt more smooth.
True. I don't think these platforms are as similar as some of my comments in this thread may have led people to believe I do, but both invoke "not quite 16-bit" and sometimes "Famicom but more colorful" feelings from me, even though the PCE obviously has more sprites and smoother gameplay. Many SMS games run smoothly too, so I can only attribute the slowdown found in a large number of games to the incompetence of their programmers. I mean, compare Daffy Duck in Hollywood against Taz in Escape from Mars and it's really difficult to believe both are running on the same console.
There is a lot of cd game with great music like lord of thunder
I rarely find CD soundtracks interesting. Sometimes it seems like the musicians are so excited about not being restricted by the hardware that they focus more on the variety of the sounds than on creating engaging melodies. At least on the Sega CD I often felt like that was the case. Nothing beats a catchy upbeat chiptune.
and many shooter too like megadrive.
Shooters and RPGs are waaaay at the bottom of my list of preferred game genres. There are a couple of shooters I like, but they're more like exceptions.
I can make a list of interesting games to try someday
By now you probably know that my favorite genre is platformers, preferably with above average graphics.
Maybe we should go back to sms vdp subject, there was some interesting information coming out and I would like to learn more about it too.
I have great interest in SMS programming myself, since it's superior to the NES in many ways, but because of poor third party support there are a lot of things we never saw it do, while the NES was practically squeezed to the last drop. It would be great if the SMS had games as good as the best NES hits, but with improved visuals.
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Re: SMS VDP data transfer bandwidth duing vblank

Post by tepples »

No mid-frame vertical scroll splits on a Master System means you won't see effects like the background of Recca, hilly roads like those of Rad Racer and Road Rash have to be rendered (slowly) in software, and even status bars have to be much simpler. So if you're making hills, you'll need all the VDP data transfer bandwidth you can get.
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Re: SMS VDP data transfer bandwidth duing vblank

Post by tokumaru »

True, that's one significant disadvantage of the SMS compared to the NES. But you can still fake a little bit of detail in scroll splits by using clever tricks. For example, if you have a big boss that moves up and down made of background tiles, you could draw the floor using striped patterns (like those found in similar situations in NES Mega Man 1 and 2, which didn't do scroll splits) that are easily updatable to compensate for the vertical movement, and add extra detail using sprites (like the road in the intro of NES Darkwing Duck). Yes Ys on the SMS managed to draw steady colored bars in its status bar using background tiles when scrolling vertically by selectively blanking scanlines above and below the bars.

The lack of sprite flipping is another drawback of the SMS, but with good management of pattern updates you might be able to overcome that without much trouble.
Last edited by tokumaru on Wed Dec 21, 2016 8:23 pm, edited 1 time in total.
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Re: SMS VDP data transfer bandwidth duing vblank

Post by tepples »

By "Yes" you mean Ys, pronounced somewhat like "ease", right?

For a moment, I thought you were saying two prog-turned-pop rock bands from England had a SEGA-related namesake.
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Re: SMS VDP data transfer bandwidth duing vblank

Post by tokumaru »

tepples wrote:By "Yes" you mean Ys, pronounced somewhat like "ease", right?
Yeah, shit like this happens when I post from my phone...
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Re: SMS VDP data transfer bandwidth duing vblank

Post by Banshaku »

@tokumaru

If I would buy all the old game I like I wouldn't have the money or space (especially in Japan!) to do it :lol: so emulators are a good compromise.
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Re: SMS VDP data transfer bandwidth duing vblank

Post by Drew Sebastino »

tokumaru wrote:Sometimes it seems like the musicians are so excited about not being restricted by the hardware that they focus more on the variety of the sounds than on creating engaging melodies.
It always ends up sounding like a bunch of white noise to me. That's why a lot of PS1 and Saturn ports of arcade games suck to me. The graphics are pixel perfect, but they change the soundtrack, because they think it's better I guess. They might a well "upgrade" the graphics too while they're at it. :lol:
tomaitheous wrote:PCE games don't look like SMS games
I just thought I'd support this:
https://www.youtube.com/watch?v=Q-CMqe3Aa9M vs. https://www.youtube.com/watch?v=m9GOa1dxLQ4
tokumaru wrote:I can only attribute the slowdown found in a large number of games to the incompetence of their programmers.
Sounds like the same situation with some other system...
tokumaru wrote:There are a couple of shooters I like, but they're more like exceptions.
R-Type? :wink: I've found all the shooter games starting with Donpachi have been shit, being about carefully moving your ship (with digital controls) along a bunch of slow moving crap that you're not even sure how close you can get to. I'll take tests in reflexes or planning over car parking simulators any day of the week. The closest I'll ever delve into that shit is Cho Ren Sha 68K, and even that's pushing it.
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Re: SMS VDP data transfer bandwidth duing vblank

Post by tomaitheous »

tokumaru wrote:True, that's one significant disadvantage of the SMS compared to the NES. But you can still fake a little bit of detail in scroll splits by using clever tricks. For example, if you have a big boss that moves up and down made of background tiles, you could draw the floor using striped patterns (like those found in similar situations in NES Mega Man 1 and 2, which didn't do scroll splits) that are easily updatable to compensate for the vertical movement, and add extra detail using sprites (like the road in the intro of NES Darkwing Duck). Yes Ys on the SMS managed to draw steady colored bars in its status bar using background tiles when scrolling vertically by selectively blanking scanlines above and below the bars.
From the SMS perspective, this has always been interesting to me. System design wise, the SMS is very "clean" for the most part. Proper hsync interrupts and such, but why wouldn't they have Y mid screen updates. That baffles me. The choice for a small tilemap size is also weird. Under normal game conditions, it's fine - but depending on some effects, the small tilemap makes it difficult or impossible.

There are a number of clever ways SMS games do to get status windows, or floors, and mid screen scrolling. Dragon's Trap uses char scrolling for Y movement, and fine scrolling for X movement of the bosses. It actually works out pretty decent. Cool Spot turns off the display, and then re-enables it with a BG relocation mid screen (change BG map pointer), and finished it off with sprites in the new status bar area. I couldn't tell from the crappy debugger, but that's what it appears to be doing.
The lack of sprite flipping is another drawback of the SMS, but with good management of pattern updates you might be able to overcome that without much trouble.
Well, the trade off was tile flipping in the BG. Road Rash wouldn't have been able to do what it does without it. I think more than sprite flipping, is that fact that you can't use all 512 cells on the SMS, since the tilemap is using some of that space. I think the max is 448 cells (8x8), but I guess the flip side to that is you can allocate that however you want between sprites and tiles.
Just one thing to note; you have to be careful with SMS videos on youtube. People love to turn off the sprite limit in emulation for those videos. Makes them more impressive than they are. I remember watching the Gunstar Heroes port and being absolutely amazed.. until I tried it for myself (serious flicker).
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Re: SMS VDP data transfer bandwidth duing vblank

Post by Drew Sebastino »

tomaitheous wrote:People love to turn off the sprite limit in emulation for those videos
Oh, you're right, I just noticed... Still a pretty good port though.
tomaitheous wrote:the SMS is very "clean" for the most part.
I'd say that's a little subjective (even if "for the most part"). I never understood why they decided to use 4bpp graphics with only 2 16 color palettes. a 3bpp background layer but with 3bpp sprites being able to cover close to, if not, the whole screen would have been a much better deal to me. Doubling the palettes would also be nice too; I don't know why Sega has trouble with that... :lol:
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Re: SMS VDP data transfer bandwidth duing vblank

Post by tokumaru »

Espozo wrote:It always ends up sounding like a bunch of white noise to me.
I wouldn't necessarily call it white noise, but more often than not, PCM/CD music sounds uninteresting, boring or just plain weird compared to "proper" video game music. Compare the soundtrack of Sonic 3D Blast on the Genesis and on the Saturn. I think the Saturn version is pure crap, boring as fuck, while the Genesis one is much more memorable (but not perfect).
Not to disagree with you, but the approach one particular developer took when porting a game doesn't necessarily reflect what the platform is capable of. Sometimes ports look bad because of ROM size restrictions imposed by the publisher, so the console itself isn't to blame. Horizontal shooters will invariably suffer on platforms like the NES or the SMS, that can only show a very limited number of sprites per scanline.
Sounds like the same situation with some other system...
I never thought of that, but you may be right.
R-Type? :wink:
Not sure if I ever gave R-Type a proper try, but no. Since you want to know, from the top of my head, the only shooters I remember having enjoyed playing (as in "played more than once" and "played more than one level") are Tyrian 2000 for DOS and Ikaruga on the Dreamcast.
tomaitheous wrote:System design wise, the SMS is very "clean" for the most part.
I agree. I never programmed for it, but looking at the docs, everything is very concise and straightforward, it just makes sense. The NES appears to have way more quirks.
The choice for a small tilemap size is also weird. Under normal game conditions, it's fine - but depending on some effects, the small tilemap makes it difficult or impossible.
It bothers me a bit that to have something as simple as glitchless horizontal scrolling you have to mask the leftmost 8 pixels of the screen and end up with a weird 248-pixel wide viewport (I know this often happens in the NES as well - and you still get attribute glitches!). Other than that, I don't see any problems.
Dragon's Trap
Never played it, but looking at videos now, that's a very nice looking game at times! Some backgrounds look great, like this one, but then they go and mix that with crap like this... go figure. Characters look consistently good though!
Cool Spot turns off the display, and then re-enables it with a BG relocation mid screen (change BG map pointer), and finished it off with sprites in the new status bar area.
I don't see any relocation, it just appears to blank some scanlines to smooth out the transition between the gameplay window and the status bar. The sprites are nicely spread though, and cover a decent enough amount of the the status bar area to not look weird. Earthworm Jim uses sprite magnification to cover a bigger area, but it looks a little weird IMO (and AFAIK magnification doesn't work on all VDP variants).
Well, the trade off was tile flipping in the BG.
When you say it's a trade off do you mean that there's a hardware justification for why both couldn't be implemented or that it's a trade off when compared to the NES? The Good thing about the NES is that while it doesn't support background tile flipping natively, this feature can be implemented by a mapper in the cartridge.
I guess the flip side to that is you can allocate that however you want between sprites and tiles.
I like the fact that the VRAM layout is configurable.
Just one thing to note; you have to be careful with SMS videos on youtube. People love to turn off the sprite limit in emulation for those videos.
That's true. People frequently do that with NES games too.
Espozo wrote:I never understood why they decided to use 4bpp graphics with only 2 16 color palettes.
There have been worse decisions... PCs had 4bpp graphics with a single constant 16-color palette in EGA... now *that* sucked. I can think of a lot of cool things to do using the Master System setup.
a 3bpp background layer but with 3bpp sprites being able to cover close to, if not, the whole screen would have been a much better deal to me.
Sounds cool, but we got what we got. I see no point in dreaming about hardware that doesn't exist unless we can actually get it made.
Doubling the palettes would also be nice too; I don't know why Sega has trouble with that... :lol:
They did, for the Genesis. :mrgreen: Sure, by the time they did it, 4 palettes was pretty lame.
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Re: SMS VDP data transfer bandwidth duing vblank

Post by Drew Sebastino »

tokumaru wrote:more often than not, PCM/CD music sounds uninteresting, boring or just plain weird compared to "proper" video game music.
That kind of reminds me how I much prefer the original Street Fighter II games over the Super Street Fighter II games, mainly because of how they changed the music (and the announcer sucks). I generally find PCM better, but then you also get the early SNES games that sound like a midi file played with the worst possible sound font, recorded, then played at the lowest sampling rate possible. I actually really like the music in the Donkey Kong Country games. Not only is there a clear melody, but the instruments all sound excellent.
tokumaru wrote:I never thought of that, but you may be right.
To be fair, this comes to mind with many systems. I don't think any have had it as bad as the Jaguar though. People really undermine how much of an influence bad programming has on why a game may be performing poorly. Nowadays, it's baffling to me why people automatically assume it's the hardware. It could be infinitely powerful, but I'm sure somebody would program something infinitely bad, and whenever the hardware gets more powerful, there's less of a reason to make it as efficient as possible. I remember looking the other day at what the minimum specs were for Microsoft Word, and it was something crazy like a 1+ GHz, dual core CPU with 2GB of ram. Give me a break. :lol:
tokumaru wrote:That's true. People frequently do that with NES games too.
I really don't know why someone would play the SMS version of R-Type on an emulator just to artificially make it look better, when they could just play the original arcade version on MAME...
tokumaru wrote:Sounds cool, but we got what we got. I see no point in dreaming about hardware that doesn't exist unless we can actually get it made.
True. Reminds me how one of the first things I did when I went here is ask why the SNES couldn't have more palette entries (much before I even knew what I was talking about.) I'm probably the only person on this website that thinks that. (Which is why I'm trying to make a system to have sprite palettes changed mid screen.) The good old days of two years ago... :lol:
tokumaru wrote:They did, for the Genesis. :mrgreen: Sure, by the time they did it, 4 palettes was pretty lame.
It's just strange to me, because I've always considered the amount of color palettes to be the main thing arcade boards led consoles by. (the SNES only had 16, while most arcade board I've seen from the time had 256) I don't think we ever had a 2D system (Neo Geo notwithstanding) with a separate chip for holding color data, instead having it inside the video chip. It became really bizarre with the GBA, with it's hardware leaving anything that wasn't a Sega amusement park ride from the time period in the dust. 4 8bpp layers isn't entirely useful when they're fighting for one palette...
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