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Atari v Commodore


stevelanc

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Andy... he is talking about Star Raiders... you mentioned SR2... (and have a look on the A8 version which is good... ;) mode9 planetscape... f.e.)

 

http://atari.fandal....butt_details_x=

 

 

I thought the video I linked to was Star Raiders 1 ?

 

I was sure someone mentioned earlier in the thread about wanting to see SR2 on the 64 ? That's why I linked to the 64 version of SR2..

I guess it's a not enough coffee situation this morning for me, maybe ;)

 

 

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I'd like to see a Commodore 64 version of Star Raiders. Maybe one of you super-coders can do it, and jazz it up to surpass the A8 original with more color, etc. Could the C64 do a "color" version of Star Raiders?

 

i have to say that this one appeals to me :)

 

yes you could do Star Raiders in colour. the only potential stumbling block i can see is the use of "particle" graphics for explosions, which drags down the 1.8mhz atari chip so is certain to have a similar impact on the c64. however i would have thought that the use of c64 sprites to generate the rest of the graphics would compensate somewhat.

 

however the 64 already has a Star raiders clone called Sentinel

My link

 

 

Yes, Sentinel is a great game. Interestingly, it wasn't released for ATARI, even though it was a Synapse game.

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Have you ever taken a closer look at Rescue on Fractalus? Behind the scene?

Or just watch the videos on youtube again.

 

C64 is already doing all that stuff...

-No VBI fixed graphics

-Drawing closer ranges more often than distant ones.... and so on....

 

.... while the Atari is simply drawing frame per frame , beeing allmost 3x as fast ?

 

What will we see on the A8 after using all those speedup tricks?

The C64 version is doing double buffering just like the Atari version, and it doesn't draw closer ranges more often. Also it's not 3x speed on Atari but 2x speed (Atari: 6 fps, C64: 3 fps).

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Couldn't you do a mode 7 type effect by taking the top down graphics as per traditional racing games of that type (which essentially what F-Zero is using) and use a dirty hack to draw the bottom line in double pixel width and gradually up to the top line in 1/2 pixel width?

 

I'm sure there is an Amiga demo which does something similar to this to simulate a quick and dirty Mode 7 effect.

 

edit: on a per char block system not each individual pixel at a time.

Edited by oky2000
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Couldn't you do a mode 7 type effect by taking the top down graphics as per traditional racing games of that type (which essentially what F-Zero is using) and use a dirty hack to draw the bottom line in double pixel width and gradually up to the top line in 1/2 pixel width?

 

I'm sure there is an Amiga demo which does something similar to this to simulate a quick and dirty Mode 7 effect.

 

edit: on a per char block system not each individual pixel at a time.

 

That's kind of what Mode7 is doing anyway. For a fully textured one its the progress through the map by adding offsets (and calculating those offsets per line) and then plotting them to the screen that's slow. A top down version has to do basically the same thing and to make it Mode7 style you've got to add that extra calculation back in, so without some other massive cheat method you've basically got the same amount of work to do.

 

*edit*

Should I create a thread over on TMR's new forum for this stuff? It seems a lot of people are interested in at least thinking about having a go so better to take it somewhere where it's less off topic.

 

Pete

Edited by PeteD
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I would get involved definitely, and both platforms are ok to me...

I have some routines for software sprites and texture maping on C64 as work in progress and am messing with GTIA modes and 3d on A8 so I'm up for challenge.

 

And I like JamesD's idea to share code or at least share general methods and algorithms. This whole thread is one big comparisson of special features of A8 and C64. And by now we know at least in theory what those are, so lets see how do they measure up in real application. If someone shows a game that looks better on one computer, someone from another team will dissasemble it anyway or simply ask "how did you do that?" and use that sort of code (if its usable) to improve his version.

Yes, it will come later, and someone will say "we were first..." but final result is true as it gets.

 

It seems to me ideas are more important than actual code, like the code in middle of A8 YOOMPs tunnel mapper, or screen drawing in C64 Last Ninja ... Those are ideas that could be used on other computer with similar effect...

 

Happy coding! :)

Sharing ideas is most important but if you don't share code it's inevitable that one team or the other will have some tweak the other team misses.

If teams could discuss how they approach certain problems and share code then there is potential for teams to find further optimizations.

It would also give a few 6502 coders some bragging rights if they find a more optimal way of doing something.

If someone could host some sort of version control (subversion?) then sharing documentation, source, etc... would be easy.

Some sort of online status would have to be maintained as well.

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I'd like to see a Commodore 64 version of Star Raiders. Maybe one of you super-coders can do it, and jazz it up to surpass the A8 original with more color, etc. Could the C64 do a "color" version of Star Raiders?

 

i have to say that this one appeals to me :)

 

yes you could do Star Raiders in colour. the only potential stumbling block i can see is the use of "particle" graphics for explosions, which drags down the 1.8mhz atari chip so is certain to have a similar impact on the c64. however i would have thought that the use of c64 sprites to generate the rest of the graphics would compensate somewhat.

 

however the 64 already has a Star raiders clone called Sentinel

My link

 

 

Yes, Sentinel is a great game. Interestingly, it wasn't released for ATARI, even though it was a Synapse game.

 

 

Final Orbit on ATARI 800 from Sirius Software looks very simular.

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I'd like to see a Commodore 64 version of Star Raiders. Maybe one of you super-coders can do it, and jazz it up to surpass the A8 original with more color, etc. Could the C64 do a "color" version of Star Raiders?

 

i have to say that this one appeals to me :)

 

yes you could do Star Raiders in colour. the only potential stumbling block i can see is the use of "particle" graphics for explosions, which drags down the 1.8mhz atari chip so is certain to have a similar impact on the c64. however i would have thought that the use of c64 sprites to generate the rest of the graphics would compensate somewhat.

 

however the 64 already has a Star raiders clone called Sentinel

My link

 

 

Yes, Sentinel is a great game. Interestingly, it wasn't released for ATARI, even though it was a Synapse game.

 

 

Final Orbit on ATARI 800 from Sirius Software looks very simular.

Well, it doesn't look as good as Sentinel, but I'd have to play it.

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Have you ever taken a closer look at Rescue on Fractalus? Behind the scene?

Or just watch the videos on youtube again.

 

C64 is already doing all that stuff...

-No VBI fixed graphics

-Drawing closer ranges more often than distant ones.... and so on....

 

.... while the Atari is simply drawing frame per frame , beeing allmost 3x as fast ?

 

What will we see on the A8 after using all those speedup tricks?

The C64 version is doing double buffering just like the Atari version, and it doesn't draw closer ranges more often. Also it's not 3x speed on Atari but 2x speed (Atari: 6 fps, C64: 3 fps).

 

Dream on.

 

Check at 3:02 ff...

 

 

 

Yousimply can't find this here:

 

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Couldn't you do a mode 7 type effect by taking the top down graphics as per traditional racing games of that type (which essentially what F-Zero is using) and use a dirty hack to draw the bottom line in double pixel width and gradually up to the top line in 1/2 pixel width?

 

I'm sure there is an Amiga demo which does something similar to this to simulate a quick and dirty Mode 7 effect.

 

edit: on a per char block system not each individual pixel at a time.

 

That's kind of what Mode7 is doing anyway. For a fully textured one its the progress through the map by adding offsets (and calculating those offsets per line) and then plotting them to the screen that's slow. A top down version has to do basically the same thing and to make it Mode7 style you've got to add that extra calculation back in, so without some other massive cheat method you've basically got the same amount of work to do.

 

*edit*

Should I create a thread over on TMR's new forum for this stuff? It seems a lot of people are interested in at least thinking about having a go so better to take it somewhere where it's less off topic.

 

Pete

 

The difference is if you are doing a quick and dirty version you can reduce the steps between double and half pixel interpolation per line and do it on an 8 scanline basis per charblock x screenwidth too though surely?

 

Also you can do a sharper angle unlike F-ZERO which doesn't look right as the horizon is too high up. If you did it as 12 chars high or less to get the horizon in the middle it would probably look better too. Whether all these shortcuts compared to how F-Zero is drawing it is enough is another matter though ;)

 

(C64 and 65xx ASM is not my strongpoint and nor is this kind of maths involved...i'm more your blitter/copper/dpaint demon haha)

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Have you ever taken a closer look at Rescue on Fractalus? Behind the scene?

Or just watch the videos on youtube again.

 

C64 is already doing all that stuff...

-No VBI fixed graphics

-Drawing closer ranges more often than distant ones.... and so on....

 

.... while the Atari is simply drawing frame per frame , beeing allmost 3x as fast ?

 

What will we see on the A8 after using all those speedup tricks?

The C64 version is doing double buffering just like the Atari version, and it doesn't draw closer ranges more often. Also it's not 3x speed on Atari but 2x speed (Atari: 6 fps, C64: 3 fps).

 

Dream on.

 

Check at 3:02 ff...

 

 

 

Yousimply can't find this here:

 

 

I can't really notice any difference apart from the faster frame rate....what am I meant to be looking for in each vid?

 

Whatever is the problem with C64 RoF causing the speed difference it is significantly reduced by the time you get to Eidolon on A8 vs C64 that's for sure....and I doubt it is any specific optimisation that couldn't be applied to the A8 6502 machinecode from the C64 6510 machine code either.

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I can't really notice any difference apart from the faster frame rate....what am I meant to be looking for in each vid?

 

 

 

Since you have seen the video, you might not be blind or else, i guess?

 

The C64 version is not updating all graphics data at the same time. Wherever possible, the graphics don't get changed. This makes the game look faster than it actually is. As long as you move a simple direction, it might even look ok on the C64. Do a rotation and break your eyes.... or see how slow the game really is.

It's the same in the eidolon. The games look similar fast, but in the rotations you see almost 2 frames when C64 hardy does one....

 

 

The Atari version's draw all screen content at the same frame.

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I can't really notice any difference apart from the faster frame rate....what am I meant to be looking for in each vid?

 

Whatever is the problem with C64 RoF causing the speed difference it is significantly reduced by the time you get to Eidolon on A8 vs C64 that's for sure....and I doubt it is any specific optimisation that couldn't be applied to the A8 6502 machinecode from the C64 6510 machine code either.

 

There isn't apart from the frame-rate.. One of the helping factors to RoF on the A8 is the half-resolution (and the reduced DMA stealing in this mode), which the C64 doesn't have, but still has to draw the doubling, quite why it's as slow as it as is a mystery to me though.. It shouldn't be that slow, and as seen in Eidolon, both are running (I think) at full vertical resolution, which explains why the A8 isn't quite so much faster on that, other than the 30% or so extra cycles it has per frame..

 

So up there in planet cloud-land it might be 3x faster, but on planet-earth it's quite another story ;)

 

 

But this half vertical resolution thing is a disgusting and dirty practice that should have been outlawed a long time ago :)

Edited by andym00
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The C64 version is not updating all graphics data at the same time. Wherever possible, the graphics don't get changed. This makes the game look faster than it actually is. As long as you move a simple direction, it might even look ok on the C64. Do a rotation and break your eyes.... or see how slow the game really is.

You are wrong. The game renders the same as the A8 version. Actually it would be SLOWER only to render the front stuff and keep the back stuff the same since it would require a good amount of extra processing power + another buffer to store the background + lots of masking and combining.

 

The Atari version's draw all screen content at the same frame.

Just like the C64 version.

 

Apart from the frame rate they are the same, and the frame rate factor (2x) is pretty much what you would expect from a 50% faster CPU + hardware double rasterline mode.

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The C64 version is not updating all graphics data at the same time. Wherever possible, the graphics don't get changed. This makes the game look faster than it actually is. As long as you move a simple direction, it might even look ok on the C64. Do a rotation and break your eyes.... or see how slow the game really is.

You are wrong. The game renders the same as the A8 version.

 

Slow the emulator down and you can see the refresh happening without tearing, so it's synchronised to the vertical blank; there's some moments where only bits move but that's not the game avoiding those updates, it clears the entire bitmap out each refresh and chunks the data back in and those "static" areas are redrawn. Interestingly, if you "break" the colour map for one of the buffers and slow the emulator down a bit, you can even count the frame refreshes off and see that turning is at the same speed as going straight in fact.

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Too bad half vertical didn't come with twice the color. I like the double scan line look, but only when it's very colorful.

 

If you run at 160x192 and split all the playfield colours each scanline, can you do a sort of half arsed APAC and get four colours at four lumas, 160x80?

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I can't really notice any difference apart from the faster frame rate....what am I meant to be looking for in each vid?

 

 

 

Since you have seen the video, you might not be blind or else, i guess?

 

The C64 version is not updating all graphics data at the same time. Wherever possible, the graphics don't get changed. This makes the game look faster than it actually is. As long as you move a simple direction, it might even look ok on the C64. Do a rotation and break your eyes.... or see how slow the game really is.

It's the same in the eidolon. The games look similar fast, but in the rotations you see almost 2 frames when C64 hardy does one....

 

 

The Atari version's draw all screen content at the same frame.

 

That's a feature of craptastic Youtube videos :)

 

I am only partially blind ;) but even I know that on VICE running RoF 64 it IS updating all sections at once really...at that framerate on the C64 you would notice.

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