Crappy C64 screen resolution

[chb]

Originally Posted by Megalomaniac

Sprites and sound were two of the C64's big strengths, scrolling being the other really obvious one. Considering that the developers were largely different, is it pure coincidence that they're also the Amiga's big advantages over the ST? Perhaps the ex-Atari guys who became Amiga Inc did consciously look at the areas where the C64 did lead the Atari 8-bits?

Sprites on the Amiga are actually pretty weak, conceptually close to the Atari 8-bit implementation and in many aspects weaker than the C64's - no flipping, smaller in size, no expansion... It's more the total lack of them on the Atari that gives the Amiga an advantage.

Sound hardware is very different from the C64, I do not think they were inspired in any way by it. I remember that in an interview, Glenn Keller (the designer of Paula) mentioned that originally, Paula was supposed to play fixed waveforms (probably square waves, very Atari like), and only during design they realized they could improve it drastically by DMA-ing the waveform from memory. That it outshines the Atari ST again rather stems from the very mediocre AY used in that computer.

[Zak]

Versions of old 2D games for other systems are really different, whereas versions of later 3D games are just the same game with the exact same texture mapping and look and people only argue about frame rates.

[Daedalus]

Originally Posted by clebin

I don't think the 2 colours per scan-line is quite right. I'm pretty sure you can have a lot more depending on the graphics mode and other tricks, but a real Atari guy would know more than me.

Indeed, most of the claims that guy is making could do with a a few caveats. I think he means the high resolution mode (320x192), which as standard can only show two colours (actually one colour with two different luminances). But, like on the Amiga, it's possible to modify the palette at each line, and even part way across the line with careful coding. Additionally, sprites can be used to show extra colours too.

Lower resolution modes do let you use more colours directly (up to 16) before resorting to "copper" tricks.

The sprites and sound on the C64 are better while the Atari has a faster CPU and a bigger palette. The C64 probably edges it, but I think the big factor is Tramiel and his aggressive price war. The original Atari 400/800 cost an arm an to manufacture and the cost-reduced 800XL came too late. Once the C64 had the momentum, only a C64-killer could've pulled Atari back into contention, and so things just drifted from there (and the reason other platforms fared better is mostly geographical)

Yes, this sounds about right. Along with sprites as mentioned above, the Atari 8-bit display hardware is very similar in many ways to the Amiga's, with the equivalent of a copper used to build the display. This allows the display resolution, palette, position etc. to be modified on the fly, so different resolutions and palettes can be used for status panels etc.

[Megalomaniac]

Zak, 3D games for the old systems were very different too, that was where the C64 suffered slightly compared to the Spectrum and Amstrad (and perhaps the Atari and BBC, due to the faster CPU). While I don't follow newer games at all, I'd imagine the 2D capabilities of each Playstation aren't wildly different to the XBoxes of the same generation?

So, Amstrad and C64 can both do 160x200 in a free choice of 16 colours, BBC only had 8 colours, and the Spectrum could do 256x192 with 15 colours, but with 7 of them just beign brighter versions of the others, and with colour placement / clash limitations. Am I right in thinking the Atari 8-bits could do 160x192 in 16 colours from anywhere in the palette (which would put it marginally above the C64 or Amstrad) or are there other limitations?

[Daedalus]

Originally Posted by Megalomaniac

So, Amstrad and C64 can both do 160x200 in a free choice of 16 colours, BBC only had 8 colours, and the Spectrum could do 256x192 with 15 colours, but with 7 of them just beign brighter versions of the others, and with colour placement / clash limitations.

It's worth bearing in mind too the different nature of the palettes in different machines. The C64 and Atari 8-bits use a chroma/luma type setup, whereas the Amstrad, Speccy and BBC all used RGB-based palettes. The number of colours alone only tells part of the story - while the C64 and A8 can both produce more colours, neither can really produce vivid primary colours.

Am I right in thinking the Atari 8-bits could do 160x192 in 16 colours from anywhere in the palette (which would put it marginally above the C64 or Amstrad) or are there other limitations?

It's a little more subtle than that. Ignoring "copper"-style methods of increasing colours, the Atari 8-bits had some additional limitations on colours. Most modes only had 4 colours available from anywhere in the palette, and that includes the 160x192 mode (2:1 pixel aspect) as well as the 160x96 mode (1:1 pixel aspect). What they did have however was an 80x192 mode (4:1 pixel aspect ratio), and that could display 16 different colours. However, they couldn't be freely chosen from anywhere in the palette. You either had 16 shades of the same colour, or 16 colours of the same brightness. The compromise mode (again, 80x192) could use 9 colours from anywhere in the palette. Without modifying the palette part-way through the display, that was the limit for the A8.

[AestheticDebris]

Originally Posted by Megalomaniac

So, Amstrad and C64 can both do 160x200 in a free choice of 16 colours,

The C64 can't actually do 160*200*16 with a.free.choice of colours. Even in the bitmap mode there are restrictions on how you can place colours. That's why it's bitmap mode is only 8K, compared to the 16K required by the Amstrad screen (which can freely place colours).

[tomcat666]

Originally Posted by AestheticDebris

That's why it's bitmap mode is only 8K, compared to the 16K required by the Amstrad screen (which can freely place colours).

Also one of the reasons why most cpc games are so crappy. Regardless of resolution you have to juggle 16k which is practically impossible for 8 bits with the MHz they had back then... There are some good ones of course but you can count them on one hand.

[saimo]

Originally Posted by chb

Sprites on the Amiga are actually pretty weak, conceptually close to the Atari 8-bit implementation and in many aspects weaker than the C64's - no flipping, smaller in size, no expansion...

Just for the sake of correctness...

C64 can't flip sprites either.
Regarding the size, things are a bit more complicated:
* OCS/ECS sprites are narrower than C64 sprites (16 pixels VS 24 pixels), but there's more to it: Amiga sprites come in 3 colors and, to match that, the C64 sprites must be multicolor, which halves the amount of horizontal pixels, bringing them to 12 (although they cover the same screen estate, as they as shown in 2:1 aspect);
* AGA sprites can also be 32 or 64 pixels.
* any Amiga's sprites can be as tall as the screen and beyond, whereas C64 sprites have a fixed height of 21 pixels.
Yep, the C64 can double the size of the sprites horizontally and/or vertically, while the Amiga can't.
(There are many other differences, but that's another story.)

[Thomas Richter]

To add to that: The Atari sprites could be size-expanded in horizontal direction (2x,4x) and in vertical direction (2x) though expansion in vertical direction applied to all players/missles at once, not individually.

On the plus side, Amiga sprite DMA channels can be reused (also without the copper) to draw more than a single sprite with a single DMA channel, just not on the same vertical line. To do the same on the C64 (or the Atari), you would need to use raster interrupts or the display list interrupt, i.e. the CPU would be required to reload sprite registers. That is all not necessary on the Amiga.

[saimon69]

Originally Posted by AestheticDebris

The C64 can't actually do 160*200*16 with a.free.choice of colours. Even in the bitmap mode there are restrictions on how you can place colours. That's why it's bitmap mode is only 8K, compared to the 16K required by the Amstrad screen (which can freely place colours).

The way the Amstrad seem to handle the screen reminds me bitplanes somehow;

For the 64 you end up having four colors in multicolor mode: aux1,aux2, background and foreground - that is due to the double binary digit per multicolor pixel; background and foreground in normal cases can change via a simple poke while auxiliaries are the same for all screen, unless an interrupt assembly routine changes them at rendering time, like i suspect many sceners use

[Bruce Abbott]

Originally Posted by Zak

EGA version looks better. Clearly. You're all biased. Look at the rider and the tents!

The EGA version has higher horizontal resolution, but the colors are all wrong - eg. tents have 2 shades of magenta, blue, or red rather than blue and yellow etc. It looks garish and unnatural like you would expect from the ZX Spectrum. Also the trees have no highlights and are the same green as the hills behind them, making the leaves look transparent - again like the Spectrum.

For some reason there are no clouds, and the tops of the railings are dark gray instead of white (which also looks unnatural). The hills have less texture and some are missing. Heavy dithering has been used all over, and the tent on the right inexplicably has blue mixed in with the magenta.

These flaws become more obvious when the image is enlarged to normal viewing size (only showing part of it here due to stupid forum image size restrictions):-



It's strange because EGA should have been able to do better than this. I suspect the images were lazily converted to EGA using a fixed 'generic' palette. The C64 conversion was done with a lot more care.

Watching the game in action I also see that the C64 version has smoother animation, and much better sound than the PC's standard 'PC speaker' - which is a fair comparison because in 1987 very few PCs had a sound card (Adlib was released in August 1987).

BTW in case you think this particular screenshot is a fluke, here's another one taken from a YouTube video of the C64 version:-



Pretty impressive detail and color from the old C64!

[Bruce Abbott]

Originally Posted by saimon69

The way the Amstrad seem to handle the screen reminds me bitplanes somehow;

That's because the Amstrad had no restrictions on where colors could be placed. So Mode 1 (with 4 colors) was equivalent to 2 bitplanes in 320x200, and Mode 0 (with 16 colors) was equivalent to 4 bitplanes but with wide pixels (160x200). In reality of course they were packed pixels, but the visual result was the same as if done with bitplanes.

[AestheticDebris]

Originally Posted by Bruce Abbott

That's because the Amstrad had no restrictions on where colors could be placed. So Mode 1 (with 4 colors) was equivalent to 2 bitplanes in 320x200, and Mode 0 (with 16 colors) was equivalent to 4 bitplanes but with wide pixels (160x200). In reality of course they were packed pixels, but the visual result was the same as if done with bitplanes.

Yes, it's much closer to a modern display in that sense. There's always a tendency these days to try and describe retro video displays in a more "PC" like way, which ends up with machines like the C64 being described as 320*200*16. Whilst there is an argument that isn't exactly "wrong" it is very much misleading as to their capabilities. The Amstrad is one of the few 8-bit machines you can use that sort of terminology and be entirely accurate.

[CCCP alert]

What is interesting is Monty on the Run for CPC uses mode zero not mode 1 but the C64 has the same sort of graphics as the ZX release. You can decide which you prefer. Usually it's the other way round, 64 port has chunky pixel bespoke graphics and the CPC gets some 4 colour mode 1 ZX port job of the 16 colour original (Manic Miner etc) so ends up much less colorful.

Either way there is nothing to praise about deciding 16kb screen and 4mhz Z80 with bad lines == much less than 4mhz performance. The CPC has ZERO innovation to help the little CPU shift the screen round at 50fps, you won't be playing anything as good as early games like C64 Terra Cresta on a 464, ST has exactly the same problem. Without innovations like character screens with colour/attribute RAM you need massive CPU grunt and some hardware assistance to scroll to overcome lack of innovation/engineering talent.

It's like having a dual clutch 8 speed gearbox on a 1.2L Ford Focus, useless and waste of time. Any idiot can shove a 16kb screen into a simple Z80 CPU, which is why many CPC scrolling gameplay areas massively shrink the screen size so on the Amstrad monitor they are about the same size as what your eyes see on an SX64 built in screen lol

[Megalomaniac]

For gameplay quality of scrolling action games, the C64 usually beats the CPC. The C64 can smoothly scroll a full screen, the Amstrad struggles to. I don't think even the most devout CPC fans will dispute that.

Still, for quality of still graphics (which is what this thread was originally about), the CPC normally wins for games which aren't pure Spectrum ports, especially for anything trying to be 'cute' or 'cartoony' (for realistic visuals the C64's palette probably wins. Purely as a graphics comparison (all of these are well regarded on the C64). :

Bubble Bobble:
Amstrad [ Show youtube player ]
C64 [ Show youtube player ]

Rick Dangerous:
Amstrad [ Show youtube player ]
C64 [ Show youtube player ]

Power Drift
Amstrad [ Show youtube player ]
C64 (PAL versus NTSC, but I'd say Amstrad beats either) [ Show youtube player ]

Turrican:
Amstrad [ Show youtube player ]
C64 [ Show youtube player ]

Cybernoid
Amstrad [ Show youtube player ]
C64 [ Show youtube player ]

Different machines taking different compromises, essentially, which is always the theme of comparisons of 8-bit systems, none of them could do everything.

[TCD]

Originally Posted by Megalomaniac

Still, for quality of still graphics (which is what this thread was originally about)

Can't find any mention of 'still graphics' in the first post.

[tomcat666]

Originally Posted by Megalomaniac

Bubble Bobble:
Rick Dangerous:
Power Drift
Turrican:
Cybernoid

Graphics wise the cartoony feel might be better on CPC, but:
Bubble Bobble - choppy on CPC, very fluid on C64, gameplay wise it is much much better
Rick D. - looks better on CPC, but gfx are smaller and somehow feels off. C64 is very much like amiga counterpart gameplay wise
Power Drift- Gfx definetly better, but it is in extreme slow motion compared to fast action on c64, gameplay again wins on c64.
Turrican- No comment
Cybernoid-Both pretty much ok

And then we come to Sound, which was not mentioned... c64 wins on all of these

You should of shown Prehistorik 2, Gryzor, Pinball Dreams

[TCD]

Originally Posted by tomcat666

Turrican- No comment

I think Turrican is a very good example why you can't just compare screenshots when talking about graphics

[Megalomaniac]

I intentionally limited to games which are available and well-regarded on both systems, a methodology which does favour the C64. The biggest international commercial publishers generally got a lot closer to the potential of the C64 (and Spectrum) than they did for the Amstrad - some of the most impressive CPC titles are the more recent homebrew creations, or from companies in France where the CPC was the main system. It's no coincidence that most of the highest rated games on CPC Games Reviews aren't the biggest name UK developed titles (with a few exceptions like Dave Perry and Hewson). Check out a few of those obscure titles before forming an opinion of the system's capabilities.

Still, it's true that the C64 usually wins for gameplay for fast 2D action games, especially scrolling ones, and for sound. Other areas are closer, or in the Amstrad's favour

[lmimmfn]

I think Savage is a good example of the C64 limitations
C64:
[ Show youtube player ]

Amstrad:
[ Show youtube player ]

Speccy:
[ Show youtube player ]

The Speccy is quite colourful but has to scroll in 8x8 chunks to avoid colour clash.

A really nice trick on the C64 to remove the blockyness is to overlay a high res sprite mask over a low res one to increase the definition, used nicely in Target Renegade:
[ Show youtube player ]

Some really impressive Spectrum pictures:
[ Show youtube player ]