A8 vs NES (Power and graphical capabilities)

[Ross PK]

I've never owned a NES. But I do know that the A8 for it's time was the or was one of the most powerful 8-bit home computers.

Edited August 16, 2007 by Ross PK

[Bryan]

I've never owned a NES. But I do know that the A8 for it's time was the or was one of the most powerful 8-bit systems.

 

The NES is capable of doing higher resolution games with a lot of color. Characters and sprites can both have multiple colors and according to Wikipedia, 25 colors on a line is not a problem. Basically, NES games look very much like the arcade originals but sometimes have sprite flicker if too many are on a line.

[Rybags]

Just reading the Wiki article.

 

The processor is a Ricoh 2A07, which is a 6502 workalike with extra functions. Speed is virtually identical to the Atari 800.

 

Graphics are only 256 horizontally, with a 48 (?) colour palette.

 

25 colours per line, 8 sprites per line (normally). 64 sprites per screen.

 

Of course, both those limitations can be overcome with software trickery.

 

Only 2K RAM in the system, but extra RAM can be in the cartridges.

 

Sound system (2 pulse channels, 1 triangle wave channel, 1 white noise channel, 1 PWM/PCM channel). From hearing limited numbers of NES games in action, I'd put the POKEY ahead in many regards.

 

 

One thing about the NES, though: it is possibly the only home computer or console to have a decent Galaga port (disregarding modern systems, which just tend to run emulation layers anyway for many classic arcade games).

Edited August 16, 2007 by Rybags

[Bryan]

Graphics are only 256 horizontally, with a 48 (?) colour palette.

Well, most games on the A8 end up being 160 across. The 256 mode is nice because it gives you square pixels and characters.

 

Only 2K RAM in the system, but extra RAM can be in the cartridges.

The NES doesn't have a bitmap for the screen, but rather reads character and sprite data from a separate bus to the cartridge. This keep the RAM requirements down, but doesn't allow manipulation of the screen on a pixel basis. It's very similar to many arcade games of the early 80's.

 

Sound system (2 pulse channels, 1 triangle wave channel, 1 white noise channel, 1 PWM/PCM channel). From hearing limited numbers of NES games in action, I'd put the POKEY ahead in many regards.

 

NES music is certainly distinctive. The NES chip has some digital capability, which is nice.

[Fröhn]

Well, most games on the A8 end up being 160 across. The 256 mode is nice because it gives you square pixels and characters.

Pixel aspect in NES/SMS 256 mode is about 1.5:1, while A8 has a pixel aspect of 1.05:1 (in 320x192 mode). The NES/SMS has VERY un-square pixels.

[Heaven/TQA]

Fröhn...but not in antic mode e or 12.

[Bryan]

Well, most games on the A8 end up being 160 across. The 256 mode is nice because it gives you square pixels and characters.

Pixel aspect in NES/SMS 256 mode is about 1.5:1, while A8 has a pixel aspect of 1.05:1 (in 320x192 mode). The NES/SMS has VERY un-square pixels.

 

Actually, a perfect 4:3 screen is 256x192. The Atari's screen is about 5:3 squished horizontally, so an 8x8 cursor is a rectangle.

 

Look at this picture:

 

Notice how the characters 'EN' in LICENSED and the word 'OF' form an almost perfect square?

[atarixle]

I think, the NES is more comparable to a C64 ... what do you think?

[Artlover]

I think, the NES is more comparable to a C64 ... what do you think?

No.

[atarixle]

Nice short and clear answer :-)

 

The German Wikipedia-Page has a nice overview over the technical specifications: http://de.wikipedia.org/wiki/Nintendo_Entertainment_System

Edited August 16, 2007 by atarixle

[Fröhn]

Actually, a perfect 4:3 screen is 256x192. The Atari's screen is about 5:3 squished horizontally, so an 8x8 cursor is a rectangle.

This has nothing to do with pixel aspect. Without knowledge of the pixel aspect, you cannot determine if a resolution is 4:3 or 5:3 because you don't know what X and Y sizes the areas have on screen.

 

For example, A8 160x192 has is a 7:4 screen because every pixel is 2.1 times wider than high (pixel aspect 2.1:1).

 

Also: The NES has 256x240 and not 256x192.

Edited August 16, 2007 by Fröhn

[Bryan]

Actually, a perfect 4:3 screen is 256x192. The Atari's screen is about 5:3 squished horizontally, so an 8x8 cursor is a rectangle.

This has nothing to do with pixel aspect. Without knowledge of the pixel aspect, you cannot determine if a resolution is 4:3 or 5:3 because you don't know what X and Y sizes the areas have on screen.

 

For example, A8 160x192 has is a 7:4 screen because every pixel is 2.1 times wider than high (pixel aspect 2.1:1).

 

Right, I know all that. The pixel clock (instead of the horizontal resolution) determines the width of the pixels. The 64's pixels are narrower than the A8's because the clock is a little faster, making the left and right borders a little wider. Still, a box with an equal number of pixels on each side will not be square on an A8 in any mode.

 

Also: The NES has 256x240 and not 256x192.

 

And...... no one uses all 240 because they'd go off the screen, just like they would if you tried to draw 240 lines on the Atari (or any system). Most NES games leave off several rows.

[Bryan]

Here's a picture of my A8's screen. The picture is of a quickly drawn 17x17 text mode box. Each block is an 8x8 character, so it's a 136x136 "square."

 

Fig 1 shows how it looks on a monitor with a normal aspect ratio and reasonable borders.

 

Fig 2 shows how much I had to squish it to make it square. Is your display really that far from mine?

 

Fig 3 is where I took the original picture and cut the right 1/5th of of the screen off, giving me approximately 256 pixels across. When stretched out to the same width as the others, the box looks square again. This means that if a video chip were to draw 256 pixels in the time it takes to draw an Atari Normal width playfield line, the pixels would be square.

 

This is why the NES has square pixels. It has a pixel clock in between the Atari 320 and 160 mode clocks.

[peteym5]

The NES is newer technology, so it is going to better (in some aspects). But if I am not mistaken, the NES had tilemapped (aka character mapped) screens with a limited pallette. Also the NES had a sprite system similar to the Commodore 64. This is why you see alot of side scrollers on the NES. You won't see anything that requires extensive pixel mapping, which is what Atari 8-bit is more able to do.

 

The other advantage Atari had was a palette of 128/256 colors instead of 48. The limit was only a few colors on the screen at ounce, unless DLIs were used. Both systems suffer from limited number of sprites and they have to flash between alternate tv frames. The Atari could do DLIs to split the player/missile graphics into more sprites if they only existed in different horizontal divisions of the screen.

[Fröhn]

Right, I know all that. The pixel clock (instead of the horizontal resolution) determines the width of the pixels. The 64's pixels are narrower than the A8's because the clock is a little faster, making the left and right borders a little wider. Still, a box with an equal number of pixels on each side will not be square on an A8 in any mode.

Right. A8 pixels are not 100% square, C64 pixels are not 100% square. But they are NEARLY square in hires mode.

 

The NES pixels however are really badly un-square.

 

Also: The NES has 256x240 and not 256x192.

 

And...... no one uses all 240 because they'd go off the screen, just like they would if you tried to draw 240 lines on the Atari (or any system). Most NES games leave off several rows.

Sorry, I was talking PAL here (since you come from Florida I have to mention). On PAL, around 280 rasterlines are visible.

 

This is why the NES has square pixels. It has a pixel clock in between the Atari 320 and 160 mode clocks.

The A8 320 mode and the C64 320 mode are quite close to square pixels. But the NES is WAAAAY unsquare (same as SMS due to same pixel clock). You can easily see this by looking at the 8x8 pixel fonts used everywhere. Ofcourse, the 160 modes are even more unsquare, but atleast they are close to the 2:1 pixel aspect which is easy to work with for graphic artists. 1.5:1 like on NES is really fucked up.

[+MrFish]

Comparing the pixel aspect ratios for these systems is the least important thing, except to say that the NES has higher resolution in MULTI-color.

 

For text, I like the Atari's smaller characters better. For larger text in high resolution you need to resort to bitmaps (usually), but it still can look nice. The downside is multi-color text for the Atari (C64 has a much better design for this also).

 

One comparison that stands out in my mind, aside from the obvious hardware differences, is the way Nintendo maintained a high level of quality control over third party software houses. This eliminated many of the inevitable "dogs" that had so plagued the console/home computer market in the period prior to the NES.

Edited August 17, 2007 by MrFish

[DamageX]

On an NTSC TV, to get square pixels (for non-interlaced display) you would need a pixel clock exactly between the NES and the Atari ~6.26MHz (coincidentally, if you multiply that by four you get the pixel clock used by a VGA card to display 640x480x60hz).

 

The colors on the NES are set up as 12 hues with 4 luminances each, plus black (don't say black isn't a color). I would say the NES PPU, as it's called, most resembles the TMS9918 but with the improvement of 2bpp and putting the sprite attributes table on the chip, instead of in external RAM/ROM, for speed.

[carmel_andrews]

Can't remember where i saw/read about it (but def. on the internet) there was a website that showed an A8 setup developing software for the NES...not too sure if it was official, all i remember of it, it included a pcb (probably a cut down version of the nes/famicom h/w) a joypad interface and an interface to connect it to the Atari 8bit and lastly a MAC65 cart

[Fröhn]

On an NTSC TV, to get square pixels (for non-interlaced display) you would need a pixel clock exactly between the NES and the Atari ~6.26MHz (coincidentally, if you multiply that by four you get the pixel clock used by a VGA card to display 640x480x60hz).

6.26 MHz? How do you come up with that? Isn't two hires pixel exactly one dot clock and because of that, artefacting works? That would result in 7.159 MHz pixel clock.

 

For square pixels on a 60 Hz NTSC system, you need 6.136 MHz according to my sources.

[peteym5]

You know I find the fact of point if the pixels were perfectly square kinda pointless. The advantage the NES and maybe even the C64 had was more onscreen colors at once. If the Atari could do more onscreen colors, it would have done better in the market. The Atari did get around more onscreen colors with Display List Interupts, GTIA modes, and overlaying player/missile graphics.

 

I am working on a Retrogame that with extensive DLI use, gets about 30 to 40 colors on a character mapped (Antic 4) screen. The game is a side scroller with different floors. Between the floors, it executes a DLI to change color registers and player positions for more sprites. It also sets bit 5 in prior so 2 overlapping players generates a 3rd color. It does take some programming and expermental testing to make this possible.

 

I think the Nintendo 8-bit is a great system from its day. I think the best games were built around its hardware limitions and tried not to exceed them. The poor ones seemed poorly programmed and buggy. Did anyone see that someone started a supermario 3 clone on the Atari, but he abondaned the project? Something about the source code being lost also.

Edited August 18, 2007 by peteym5

[analmux]

Did anyone see that someone started a supermario 3 clone on the Atari, but he abondaned the project? Something about the source code being lost also.

 

pete, please read up what I replied in this thread:

 

http://www.atariage.com/forums/index.php?showtopic=111305

[vdub_bobby]

A good way to see the differences between A8 and NES display hardware is to look at Ballblazer and Gauntlet on both machines.

 

The NES was designed make it very easy to get a lot (for the time) of colorful sprites on top of a scrolling, tiled background.

 

EDIT: For more detailed info, check out several threads in the 7800 forum. They are comparing the 7800 to the NES, but some of the comparisons (sound hardware) is similar and there is a lot of detail about the NES hardware. I'll see if I can dig up some of those threads.

 

EDIT II: This thread is the best one. Some good quotes:

Eric Ball

1. The NES can produce 53 colors (black + 4 grey/white + 4 shades of 12 colors), using a method very similar to the 2600/7800 (which had 256 colors: 16 shades of 15 colors & greyscale) with 4 luma values for each chroma phase. The 3 NES color emphasis bits could be used to create additional colors, but not on a per pixel basis (maybe per line). The one advantage with the NES is all of the colors (other than black) have a higher base luma than the 7800, so are inherently brighter than 50% of the colors on the 7800.

2. I suspect that some of Bry's judgements have more to do with the TV he has than the inherent limitations of the 7800.

3. The NES NTSC pixel aspect ratio is about 10:9, while the 7800 NTSC pixel aspect ratio is 5:3 (160) or 5:6 (320). The closest to square pixels is a PAL 7800 in 320 mode, where the pixels are very, very close to square.

 

I've also been looking at the sound capabilities of the NES and there is no contest, even against a POKEY. DMA streamed delta modulation for sampled sound! Wow!

 

More Eric Ball:

The NES has a fixed 32x30 tile map (with scrolling), with 8x8 tiles. The tiles are 3 colors (plus background/transparent), with a block of 2x2 tiles having the same palette (of 4).

...

The NES has 64 sprites (max 8? per line), though it may be possible to change this on the fly to increase the total number of sprites displayed. Each 8x8 or 8x16 sprite has 3 colors (plus background/transparent) out of 4 different palettes (different palettes than tiles).

Edited August 17, 2007 by vdub_bobby

[A Sprite]

As long time NES fans who never even heard of the Atari 8 bits before entering this forum, Kamaria and I may have a unique perspective on what the Atari 8 bits can do better than the NES.

 

Or just as likely not, since it's no secret the NES was color limited, and tile based.

 

Anyways, here are the two games that impressed us the most:

 

 

Rainbow Walker

 

Neither could be done on an NES without compromise.

[Ross PK]

^ I can't actually imagine The Eidolon being faithfully reproduced on the NES.

 

Which makes me think, could Mercanary be done as good or better on the NES?

[peteym5]

Did anyone see that someone started a supermario 3 clone on the Atari, but he abondaned the project? Something about the source code being lost also.

 

pete, please read up what I replied in this thread:

 

http://www.atariage.com/forums/index.php?showtopic=111305

 

Yes, I have seen your reply. Wondering what the status on this project was and track down the programmer.