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Old 09 March 2018, 03:22   #41
albino
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Originally Posted by Estrayk View Post
I'm not a coder but as user, I can tell that seeing a game like "ENCHANTED LAND" in Atari ST, I can't see a big difference between both computers in graphics or movement. As you can see in videos, the experience in Atari is more close to Amiga that a lot of people thinks. 10 Parallax Sync Scrolling, transparency, more of 16 colors, copper sky, 50fps.... the difference isn't too big for a user point of view.
This game it runs in a standard Atari ST520 from 1985.
All of us are sure that Amiga is more powerful, but a ST isnt so far
Are you kiding?

this game is a flip screen game, only the intro show some fancy parallax and smooth scrolling..and it is supposed to be a top st optimised code done by highly skilled st demo maker...
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Old 09 March 2018, 07:57   #42
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Originally Posted by albino View Post
Are you kiding?

this game is a flip screen game, only the intro show some fancy parallax and smooth scrolling..and it is supposed to be a top st optimised code done by highly skilled st demo maker...
This is true. Pretty sure it was coded by nik of the carebears who were excellent demo coders around that era. It uses the sync scroll routine they came up with that allows tge st to scroll 4 pixels horizontally at 50 frames.

The game is an st to amiga port, but i bet the st is working a damn lot harder than the amiga version to produce the same result.

Last edited by mcgeezer; 09 March 2018 at 16:59.
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Old 09 March 2018, 09:19   #43
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Originally Posted by dlfrsilver View Post
He is also famous for quoting "The STe hardware scrolling is so rubbish that even my software routine was faster on Toki"
Well, there's nothing wrong with the Atari STE hardware scrolling. In fact, it works like expected. So what does "rubbish" mean?
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Old 09 March 2018, 09:40   #44
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Originally Posted by dlfrsilver View Post
Just for information, he was really the best if not one of the best 68000 coders.

He taught to Pierre Adane how to correctly program the amiga, and in the best optimized way. We owe indirectly to him the good ports of snow bros and pang.

Mcoder also said that most Amiga games are like basic coded but in ASM 68000.

He is also famous for quoting "The STe hardware scrolling is so rubbish that even my software routine was faster on Toki"
Then he's clearly off his meds or you're misquoting him. The STe hardware scrolling is just as good as the Amigas. You could do an R type style scroling with 3 memory moves and two tiles drawn a frame for front and back buffer. Be lucky if it hits 1 % of the CPU at 50 or 60hz. Toki runs at 25 hz I'm sure you're misquoting him. Again I'd advise you to read the STe development docs and the Amiga hardware reference manual! The way the scrolling works is more or less the same between each machine btw. There's two small differences which slightly favour the Amiga. Read the manuals and you can work out what they are.

Last edited by frank_b; 09 March 2018 at 09:56.
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Old 09 March 2018, 10:01   #45
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Originally Posted by AnimaInCorpore View Post
Well, there's nothing wrong with the Atari STE hardware scrolling. In fact, it works like expected. So what does "rubbish" mean?
I think he's trying to tell us that software scrolling is more effective than using the hardware. Seems an odd position for an Amiga fan!
Very few ST games run at 50hz. There are quite a lot that run in one VBL on the Amiga. Most STe games run in one VBL too. There's a reason for that!

Last edited by frank_b; 09 March 2018 at 10:07.
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Old 09 March 2018, 10:23   #46
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Originally Posted by coder76 View Post
Atari failed pretty badly with their hardware. At first, they didn't want to use a blitter, because it was too expensive, and then when it became cheaper, they started installing it in later Atari models. By then, it was already too late, as there were too many old machines around without a blitter, so one often couldn't still use it, even if it was available. Or then make two versions of a game, one that used blitter and another for older machines. This didn't work out either. Now the remaining Atari people probably try to patch up their old games to use blitter, but the games, they will still be inferior to Amiga versions.
Every ST machine from 87 onwards has a space on the motherboard for a blitter. I have multiple ST machines with it installed. You're right though. It should have been standard on every machine. Alone it's not enough. HW scrolling is needed too. It would cost you 80% of a frame to scroll the whole screen with the blitter.

There are some ST games (not STe) which use it but it's rare. Elvira the arcade game and ghost battle use it to draw sprites and scroll the screen. Ghost battle runs at 25 fps on a blittered ST and 3 vbl without. It's being patched in now on some games. Hard n heavy and Gianna are available with pixel scrolling via the blitter. Both run at 25 fps. The STe patched versions run at 50 fps. Hardware scrolling is more efficient than using a blitter or using the CPU. Sorry Dennis!
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Old 09 March 2018, 12:15   #47
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Originally Posted by frank_b View Post
Every ST machine from 87 onwards has a space on the motherboard for a blitter. I have multiple ST machines with it installed. You're right though. It should have been standard on every machine. Alone it's not enough. HW scrolling is needed too. It would cost you 80% of a frame to scroll the whole screen with the blitter.

There are some ST games (not STe) which use it but it's rare. Elvira the arcade game and ghost battle use it to draw sprites and scroll the screen. Ghost battle runs at 25 fps on a blittered ST and 3 vbl without. It's being patched in now on some games. Hard n heavy and Gianna are available with pixel scrolling via the blitter. Both run at 25 fps. The STe patched versions run at 50 fps. Hardware scrolling is more efficient than using a blitter or using the CPU. Sorry Dennis!
Yes, you need both a blitter and horizontal HW-scroll to compete with Amiga games. But even then Atari STe doesn't have some features that Amiga has, like hardware sprites, dual playfield, and more colors (5-6 bitplanes). And the copper on Amiga is probably more flexible than Atari's display chip. Also audio was always better on Amiga with 4 channel DMA. Atari STe had 2 chan DMA, if I recall right (sure, you can mix up more channels with CPU, but that takes precious CPU time).
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Old 09 March 2018, 12:25   #48
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The biggest problem the ST series has is how fragmented the hardware is, which i'm convinced developers to drop it sooner.

You had ST's with no built in modulator
You had ST's with single side floppy drive
You had ST's with double side floppy drive
You had ST's that had a blitter
You had ST's that had more than 512k of ram

And all of this was over a relatively short space of time from 1985 to 1990

And then the STe followed in 1991 which added another configuration, and then just over another year later, the Falcon arrived which was another configuration as well.

I think if Atari had simply stuck with one machine type like Commodore, the ST would have survived longer, because at least then developers had a target in mind, on the Amiga about the only difference was "was it 512k or 1meg" and that was easy to work around and because it was so easy, 1meg ended up being the norm as it was so easy to support in software and see the benefits.
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Old 09 March 2018, 12:36   #49
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Originally Posted by Galahad/FLT View Post
The biggest problem the ST series has is how fragmented the hardware is, which i'm convinced developers to drop it sooner.

You had ST's with no built in modulator
You had ST's with single side floppy drive
You had ST's with double side floppy drive
You had ST's that had a blitter
You had ST's that had more than 512k of ram

And all of this was over a relatively short space of time from 1985 to 1990

And then the STe followed in 1991 which added another configuration, and then just over another year later, the Falcon arrived which was another configuration as well.

I think if Atari had simply stuck with one machine type like Commodore, the ST would have survived longer, because at least then developers had a target in mind, on the Amiga about the only difference was "was it 512k or 1meg" and that was easy to work around and because it was so easy, 1meg ended up being the norm as it was so easy to support in software and see the benefits.
No argument there. Hardware features couldn't be relied on to be present in every machine.

The Falcon didn't have the Microwire interface and didn't do 6 khz 8 bit sample play back like the STE.

The Mega STe and TT have no extended joystick ports.

Not every Mega ST had a blitter.

The TT had no blitter.

The TT could set all three bytes of the video address but lacked fine scrolling support.


The 1200 was totally hardware register and timing backwards compatible with the 500. Nothing was taken out of the register set.
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Old 09 March 2018, 12:41   #50
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Originally Posted by coder76 View Post
Yes, you need both a blitter and horizontal HW-scroll to compete with Amiga games. But even then Atari STe doesn't have some features that Amiga has, like hardware sprites, dual playfield, and more colors (5-6 bitplanes). And the copper on Amiga is probably more flexible than Atari's display chip. Also audio was always better on Amiga with 4 channel DMA. Atari STe had 2 chan DMA, if I recall right (sure, you can mix up more channels with CPU, but that takes precious CPU time).
I think you can do perfect Amiga ports to the STe if.

a) You don't have dual playfield in the game or have the memory to preshift and pre mask graphics
b) You stick to 4 planes
c) you have enough CPU time left for a module player or use the DMA for sound effects.
d) You're not using the sprites for an extra background layer

Parallax split screen scrolling is also possible on the STe,
If you really went to town memory wise, it would be possible to write games which aren't possible on the Amiga. The blitter on the STe can address 12 meg of memory for instance. The DMA interface is fast enough to stream 8 bit audio from a hard disk/sd card without burdening the CPU. There are games out there patched to use *real* music in game.

[ Show youtube player ]
[ Show youtube player ]
[ Show youtube player ]

Either way, both would outclass a vanilla ST quite easily for scrolling games.

Has anyone on the Amiga taken a stab at enhancing old ST game ports to use the hardware? That would be really cool.

Last edited by frank_b; 09 March 2018 at 16:03.
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Old 09 March 2018, 12:56   #51
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Originally Posted by AnimaInCorpore View Post
Well, there's nothing wrong with the Atari STE hardware scrolling. In fact, it works like expected. So what does "rubbish" mean?
Can we see the original quote(s)? I want to know if Dennis is embellishing anything he said. I can't believe anyone that smart would be stupid enough to claim software scrolling is faster than hardware.
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Old 09 March 2018, 14:27   #52
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Originally Posted by frank_b View Post
I think you can do perfect Amiga ports to the STe if.

a) You don't have dual playfield in the game or have the memory to preshift and pre mask graphics
b) You stick to 4 planes
c) you have enough CPU time left for a module player or use the DMA for sound effects.
d) You're not using the sprites for an extra background layer

Parallax split screen scrolling is also possible on the STe,
If you really went to town memory wise, it would be possible to write games which aren't possible on the Amiga. The blitter on the STe can address 12 meg of memory for instance. The DMA interface is fast enough to stream 8 bit audio from a hard disk/sd card without burdening the CPU. There are games out there patched to use *real* music in game.

[ Show youtube player ]

Either way, both would outclass a vanilla ST quite easily for scrolling games.

Has anyone on the Amiga taken a stab at enhancing old ST game ports to use the hardware? That would be really cool.
Doing real music on Amiga like Giana does would actually be incredibly easy to do

Whilst we can't play audio from fast/slow ram, the flexibility of the sample hardware is such that storing it in fast ram, and then copying chunks of data to a sample buffer in chip ram is easily possible, in fact, i'd be utterly amazed if it hadn't already been done.

As for enhancing old ST ports, other than music and samples, not really.

Whilst people like them, theres obviously only a few really great games on the ST that didn't make it, so theres no much scope to go mad.

Would be nice if the source code to some of the unreleased stuff could be found, then we could do real Amiga versions rather than slightly enhanced ST ports.
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Old 09 March 2018, 14:33   #53
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Originally Posted by Galahad/FLT View Post
Doing real music on Amiga like Giana does would actually be incredibly easy to do

Whilst we can't play audio from fast/slow ram, the flexibility of the sample hardware is such that storing it in fast ram, and then copying chunks of data to a sample buffer in chip ram is easily possible, in fact, i'd be utterly amazed if it hadn't already been done.

As for enhancing old ST ports, other than music and samples, not really.

Whilst people like them, theres obviously only a few really great games on the ST that didn't make it, so theres no much scope to go mad.

Would be nice if the source code to some of the unreleased stuff could be found, then we could do real Amiga versions rather than slightly enhanced ST ports.
I'm talking about the original Amiga versions ported from the ST Early Amiga games.

Bitmap games for instance could be enhanced properly to use the Amiga hardware.
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Old 09 March 2018, 14:55   #54
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Quote:
Originally Posted by frank_b View Post
Can we see the original quote(s)? I want to know if Dennis is embellishing anything he said. I can't believe anyone that smart would be stupid enough to claim software scrolling is faster than hardware.
OK Be my guest :

http://www.atari-forum.com/viewtopic...coder&start=25

"Le STE n'a jamais cassé trois pattes à un canard. Le blitter STE est incroyablement merdique: pour Toki, j'avais testé le blitter, et franchement, ma routine de sprites SOFTWARE allait plus vite que le hardware !!! "

in english :

"The STE is nothing to write home about. The STE blitter is incredibly shitty : for Toki, i had tested the blitter, and honestly, my SOFTWARE sprite routine was running faster than the hardware !!!"
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Old 09 March 2018, 15:03   #55
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Originally Posted by dlfrsilver View Post
OK Be my guest :

http://www.atari-forum.com/viewtopic...coder&start=25

"Le STE n'a jamais cassé trois pattes à un canard. Le blitter STE est incroyablement merdique: pour Toki, j'avais testé le blitter, et franchement, ma routine de sprites SOFTWARE allait plus vite que le hardware !!! "

in english :

"The STE is nothing to write home about. The STE blitter is incredibly shitty : for Toki, i had tested the blitter, and honestly, my SOFTWARE sprite routine was running faster than the hardware !!!"
Do you not know the difference between a blitter and hardware scrolling?

He's wrong btw. Anima's blitter routines are way faster than anything done in Toki.
I implemented his software sprite technique and basic blitter masking was *3 times* faster on two plane sprites. Anime's sprite routines are way faster than that! Preshifting is slower than using the blitter and consumes 20 times the size of the sprite data.

I can only conclude he used a general purpose bitblit implementation from the blitter manual. That routine is not suitable for games. It's too general purpose. A generic bitblit for all use cases wouldn't be usable on the Amiga either.
Looks like a classic case of an ST coder unable to properly use or understand the hardware. Lazy ST port syndrome.
Maybe he should have read the hardware manuals too.

Last edited by frank_b; 09 March 2018 at 15:45.
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Old 09 March 2018, 15:04   #56
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Originally Posted by frank_b View Post
Do you not know the difference between a blitter and hardware scrolling?
He's wrong btw. Anima's blitter routines are way faster than anything done in Toki.
Well, even the best can be wrong sometimes
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Old 09 March 2018, 15:19   #57
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Well, even the best can be wrong sometimes
Yes. The Amiga hardware reference manual avoids the complexity of a general purpose bitblit function. It focuses on simple use cases suitable for games. Low CPU overhead stuff. It's also very accessible and well written.

Atari went the other way on their blitter manual. They demonstrated one of the most complex use cases. A function which takes an arbitrary raster image at x,y coordinates at an arbitrary width and writes it to a destination raster at an arbitrary x,y position. I can hear the Amiga coders wincing at this in the background.

It costs ~1000 CPU cycles overhead (two raster) lines per call. It also requires two calls to mask. A 2k cycle overhead is way too slow for video games.

It's a shame since a simpler use case suited for sprites is the same overhead as on the Amiga. Set a few registers and go.

Last edited by frank_b; 09 March 2018 at 15:34.
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Old 09 March 2018, 15:53   #58
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Originally Posted by Estrayk View Post
I'm not a coder but as user, I can tell that seeing a game like "ENCHANTED LAND" in Atari ST, I can't see a big difference between both computers in graphics or movement. As you can see in videos, the experience in Atari is more close to Amiga that a lot of people thinks. 10 Parallax Sync Scrolling, transparency, more of 16 colors, copper sky, 50fps.... the difference isn't too big for a user point of view.
This game it runs in a standard Atari ST520 from 1985.
All of us are sure that Amiga is more powerful, but a ST isnt so far.

ATARI ST:
[ Show youtube player ]
AMIGA:
[ Show youtube player ]
That's the result of ridiculously clever coding. It doesn't prove hardware equivalence. It uses sync scrolling. That's a beam synchronous technique which allows for fine adjustment of the low 8 bits of the screen address. On an ST the hardware only allows for setting the medium and high bytes of a 32 bit address. The display always starts on a multiple of 256.

Last edited by frank_b; 09 March 2018 at 16:13.
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Old 09 March 2018, 17:53   #59
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Enchanted Lands is awesome on ST, but it's an average game for the Amiga. The same applies for Wings of Death. awesome on ST/E, but average on Amiga.
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Old 10 March 2018, 00:20   #60
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Has anyone on the Amiga taken a stab at enhancing old ST game ports to use the hardware?
I'd nominate Xenon II: AGA version using 2x4bpl dual-playfield and 64-bit wide sprites for the multiple layers. Possibly not running 50fps, but at least 25.
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