Jump to content
DracIsBack

Comparing the NES and 7800 on a technical level

Recommended Posts

I've seen more than a few posts on a few sites comparing the 7800 and the NES on a technical level. Many posters seem to feel that the "7800 was definitely behind the NES in terms of power". It is argued that the 7800 was "older technology" because it was intended for release in 1984 while the NES was released in 1985. That argument doesn't really hold because the NES was based upon the famicom, which was released in 1983.

 

Going by the specs, it seems to me that the problem was less to do with the 7800 hardware than the programmers and Tramiel cheapness.

 

Let's compare:

 

----------------------------------

CPU:

 

The 7800 uses an 8-bit 6502C. The NES also uses an 8-bit 6502. Their clock speed and processing capabilities in the core CPU seem to be fairly similar, both running at 1.79 MHz.

 

It has been argued that the NES has an edge because its Picture Processing Unit took some of the work off of the main CPU. Looking at the 7800's specs (without a programming background), it appears that the 7800 workload was also helped by it's MARIA graphics chip as well as the 2600 TIA chip.

 

In the tech specs on this site, there's a quote, which comes to mind:

 

"The 7800 mode is DMA driven, so the processor is free most of the time

to do other things, as the graphics chip runs 4 times faster than the CPU."

 

I don't have the official developer docs handy, but I also remember reading that the TIA chip in the 7800 were used to control things like joystick control, sound etc, also taking work off of the 6502C.

 

Any programmers out there want to clarify? It seems to me that the argument of the NES being helped by additional chips would also apply to the 7800.

------------------------------------------------

Memory:

 

As with most consoles, neither the 7800 nor the NES contained a lot of onboard memory. The 7800 contained 4K, while the NES contained 2K. This set both ahead of the 128 bytes that the 2600 had.

 

In terms of cartridge sizes, the NES appeared to be ahead, though the 7800 seemed to be deliberately crippled by Tramiel cheapness.

 

The NES appeared to initially be able to have game cartridges that were 128K without bankswitching. The 7800 appeared to be able to have game cartridges that were 52K without bankswitching. This put the NES ahead of the 7800, though both were beyond the typical 4K-8K games on the 2600.

 

What put Nintendo over the top was that they investigated how to use the cartridges to their fullest potential. The Tramiels were cheap.

 

Nintendo developed memory management chips to get around the 128K limit and create 256K, 384K and even 640K games for the NES. Atari didn't do this and the 7800 games never got beyond 144K.

 

Nintendo added ram to the carts. Atari told developers that this was a "no no" unless they received approval in writing from the Tramiels. Nintendo added other elements like save-game batteries to the carts. The Tramiels were too cheap.

-----------------------------------------

Graphics:

 

This gets dicey because each system seems to have certain advantages at certain functions.

 

On paper, the 7800 has higher resolution and more colours than the NES.

 

NES: 256 x 240 pixels. 13 colours on screen out of 52 colours in total.

7800: 320 x 200 pixels. 25 colours on screen out of 256 colours in total.

 

In practice, this advantage didn't always seem to show up. Many 7800 games used the 160 x 200 pixel mode, given them a black bar around the edge instead of a full screen appearence, like many NES games. Many NES games seemed to have brighter colours (despite the 7800 having a larger palette to choose from) and often used more colours (despite the 7800 having the ability to display more colours onscreen).

 

Was this a function of bad/inexperienced programming or other issues?

 

In terms of moving objects, I've heard arguments for each system. It has been said that the NES was more adept at tile-style graphics, hence the prevelance of Super Mario type games. The 7800 game library didn't have many games of this type, though SCRAPYARD DOG seemed to be programmed in this fashion.

 

On the other hand, I've also heard that the 7800 was significantly more adept at manipulating moving objects at the same time than the NES. Hence, the NES is often riddled with flickering graphics, whereas flickering almost never exists on the 7800. This seems to suggest that MARIA did indeed help out the CPU after all. Compare DARK CHAMBERS which often moves 20 or more characters with NES GAUNTLET (which flickers with only a few). One area were the NES stood out was in terms of boss creatures, though i have to wonder if this was also an issue of bad programming on the 7800. Few 7800 games featured bosses, though they did exist - MIDNIGHT MUTANTS, PLANET SMASHERS, NINJA GOLF and ALIEN BRIGADE come to mind.

 

 

 

The 7800 seemed to be a bit better at animation overall, as demonstrated by games like Tower Toppler and Ballblazer. MARIA was built to animate and it showed in these titles. On the other hand, the 7800 is often criticized for having more sluggish scrolling than the NES. This does seem to be a problem, though the system appeared to be able to scroll quickly when required (witness DESERT FALCON on a power up or SCRAPYARD DOG with a running jump). Neither the NES nor the 7800 were designed to do parallax scrolling (this was a big thing when the Genesis and TG-16 were released) though both demonstrated the ability to do this at times. On the NES, games like TEENAGE MUTANT NINJA TURTLES showed that it could be done. On the 7800, games like TOWER TOPPLER also showed this.

 

SOUND:

 

This is the big area where the NES obviously stands out. The 7800 wasn't even up to par with the Intellivision in the area, using the 2600's 2-voice RIOT chip from 1977 for its sound. On the other hand, the NES reportedly has a much more advanced 4-channel sound chip. Anyone who hears 7800 games automatically notices the problem.

 

Some 7800 games seem to create relatively inoffensive sounds and music on the limited chip (witness JINKS and its digital sound, the title music from DARK CHAMBERS and the music from MIDNIGHT MUTANTS). A few also made use of the POKEY chip in cartridge to get NES-quality sound ... Ballblazer and COMMANDO come to mind.

 

The original problem with the sound was a GCE design flaw. The problem with the sound in the games was a Tramiel cheapness issue as they almost never included a POKEY chip.

 

--------------------------------------------

 

When you compare the systems side by side on a technical level, it almost seems as though the 7800's real problem was that it didn't have the good developers pushing it to its limits and trying out new things. They were quickly porting games from systems with lesser colour palettes, weaker animation capabilities etc. They weren't being paid to develop complex games and they weren't allowed to use additional RAM, Pokey chips etc.

 

And because the 7800 was never a "big system", we never got to see third, fourth and fifth generation games that showed what the 7800 could really do once programmers got familiar with the system.

 

Like most other post-2600 systems, some 7800 games had hints of what the system was capable of but these elements didn't tie together into a strong library of games overall. Most 7800 games didn't have Ballblazer's animation, Scrapyard Dog's depth, Midnight Mutants boss creatures, Fatal Run's passwords, Tower Topplers graphics or Commando's sound.

 

In the end, this crippled the system.

  • Like 3

Share this post


Link to post
Share on other sites
----------------------------------

CPU:

 

The 7800 uses an 8-bit 6502C. The NES also uses an 8-bit 6502. Their clock speed and processing capabilities in the core CPU seem to be fairly similar, both running at 1.79 MHz.

 

On difference is that the NES 6502 doesn't support the decimal math mode which is useful for scorring and such.

 

It has been argued that the NES has an edge because its Picture Processing Unit took some of the work off of the main CPU. Looking at the 7800's specs (without a programming background), it appears that the 7800 workload was also helped by it's MARIA graphics chip as well as the 2600 TIA chip.  

 

Yes, the Maria chip handeled all the movement of graphics data from memory to the display, but when these DMA transfers where happening the CPU couldn't do anything so the DMA did cut into the usable processor cycles. Not sure if this is also the case for the NES.

 

I don't have the official developer docs handy, but I also remember reading that the TIA chip in the 7800 were used to control things like joystick control, sound etc, also taking work off of the 6502C.  

 

The TIA chip did handle the controllers and sound, but it was just an IO chip so the processor still had to do all the work. Also to make matters worse the cpu clock slowed to 1.19Mhz when the TIA is accessed.

 

In terms of cartridge sizes, the NES appeared to be ahead, though the 7800 seemed to be deliberately crippled by Tramiel cheapness.  

 

The NES appeared to initially be able to have game cartridges that were 128K without bankswitching. The 7800 appeared to be able to have game cartridges that were 52K without bankswitching. This put the NES ahead of the 7800, though both were beyond the typical 4K-8K games on the 2600.  

 

The NES used a 6502 processor which can only access 64K of address space, so 128K would be impossible without bankswitching. From a quick look at the NES tech docs it appears that it had a 32K address space for cartridges as compared to 48K on the 7800.

 

What put Nintendo over the top was that they investigated how to use the cartridges to their fullest potential. The Tramiels were cheap.

 

Nintendo developed memory management chips to get around the 128K limit and create 256K, 384K and even 640K games for the NES. Atari didn't do this and the 7800 games never got beyond 144K.

 

Nintendo added ram to the carts. Atari told developers that this was a "no no" unless they received approval in writing from the Tramiels. Nintendo added other elements like save-game batteries to the carts. The Tramiels were too cheap.  

 

The physical size of the NES carts was probably an advange since they had a lot of room to put more ROM chips.

 

Actually a number of the 7800 carts included extra RAM.

 

-----------------------------------------

Graphics:

 

In terms of moving objects, I've heard arguments for each system. It has been said that the NES was more adept at tile-style graphics, hence the prevelance of Super Mario type games. The 7800 game library didn't have many games of this type, though SCRAPYARD DOG seemed to be programmed in this fashion.

 

It's hard to compare the graphics systems on the two machines since they are radically different. The greatest strength of the 7800's graphics was it's incredible flexibility. For example where the NES sprites where either 8x8 or 8x16 pixels the 7800's could be almost any size. This flexiblity was probably also one of the 7800's biggest liabilities since it made programming the system a lot harder the programming the NES. You really had to create your own display engine for each game. For example if you wanted to have a table in RAM with the positions of your sprites and a pointer to the graphic to use for each one, you would have to write code that read this table, and then setup the data structures that the Maria used to draw the screen. Made programming more difficult, but gave you incredible flexibility.

 

Dan

  • Like 1

Share this post


Link to post
Share on other sites

I really don't know the technical terms, but look at the graphics of some games that were released both on the 7800 and NES, the 7800 looks far superior. Ditto on movement. While in some games the 7800 looks worse, for the most part it could've been a real rival. In any case, both systems have their good and bad points.

Share this post


Link to post
Share on other sites

Ok I don't understand why anyone would use 160x200 mode IF the 7800 could indeed display 25 unrestricted colours at 320x200?

 

That would make 7800 graphics look as good as Amiga graphics and better than ST but they don't! The games look more like C64 games than ST games in static terms.

 

Can someone please post the exact specifications AND restrictions of the 7800? I've searched for the mythical 'done to death' NES vs 7800 threads and haven't found one that covers things technically. If it has been done can someone point me to the thread that discusses my above questions with technical answers?

 

Thanks

 

(maybe games are more important but no programmer can make a Falcon game look identical on an ST and this is the bit I want to know about in this case, software quality is a different question to hardware capability)

Share this post


Link to post
Share on other sites

Simple answer - it cant display 25 colours unrestricted..

More like 7 colours , although the palletes can be changed every line.

Share this post


Link to post
Share on other sites

Hey thanks for the reply. I trawled through everything and got the impression the screen of 25 colours is built up in a similar way to A8 display list and Amiga Copper list yes?

 

How many unique colours per line then, 7 or 25? That's the bit I was confused with.

 

And what is the resolution (hires/lores/total colours available) for the player missile/sprites/moveable objects that the Maria (?) chip can produce and the total unique number per line if it works like the A8/C64 equivalent?

 

I'm just trying to get a feel for the system from some expert knowledge here. (NES specs are probably all over the net so not too worried about them really)

Share this post


Link to post
Share on other sites

If you really want to get the details, it's best to read the "7800 software guide" from this site:

http://atarihq.com/danb/a7800.shtml#techfiles

 

That's really the horse's mouth of it all. The little charts of specs that get published for various systems are always oversimplified.

 

 

But to basically summarize on your question:

160-mode:

max 12 colors per sprite (3 is faster)

25 colors per scanline

 

320-mode:

colors are much more limited, don't remember the specifics anymore and it's a pain to figure out :)

slower

 

Sprite size is adjustable to almost anything. Palettes and video modes can be changed between scanlines, so the most useful application of 320 is for text.

Share this post


Link to post
Share on other sites

Reading this very old thread, the issues the 7800 presented are so similar to the Jaguar!
The 7800 is indeed a very interesting system, but from a Jag-homebrew view, even more.
I love both systems, and both could have benefited from a bit of extra hardware in the box,
and more generous cartridge sizes. Jaguar is a better name though than "Atari 15600". :-)

  • Like 2

Share this post


Link to post
Share on other sites

I find the strengths of the 7800 reminds me of the Odyssey2 also: lots of moving objects, but not as strong (as the contemporary competition) with the background elements or resolution.

 

Myself, I see the 7800 in similar class to the C=64/Atari 800, with the NES/SMS in a set a bit more visually capable.

 

The former three are mostly "modified four colour" systems at a lower resolution, and "modified two colour" system at their higher resolution.

The latter three are "modified four colour" and "modified sixteen colour" systems at closer to the higher resolutions. I think the SMS is definitely an evolution from the NES towards the PC-Engine.

 

(I will be the first to say I really don't know, but...) I think the 7800 was more of a cost correction/market image correction than an enormous step beyond the 5200.

Share this post


Link to post
Share on other sites

The 7800 may have been able to compete in terms of graphics, but the sound was awful unless the cartridge used a POKEY chip, and the controllers were uncomfortable and outdated.

Share this post


Link to post
Share on other sites

It's very clear looking at NES PPU capabilities, that Nintendo was looking very hard at the ColecoVision and SG-1000, and basically doubling most everything, double the number of sprites on a line, double the number of colors in a sprite, etc.

 

The fact that the PPU had the same pixel clock as an arcade system (same as the 9918), and the same number of lines as contemporary arcade systems really was important, and really clinched the Famicom's success, its port of Donkey Kong was damned near perfect.

 

-Thom

Share this post


Link to post
Share on other sites

The 7800 may have been able to compete in terms of graphics, but the sound was awful unless the cartridge used a POKEY chip, and the controllers were uncomfortable and outdated.

 

Wow this is an old, old thread.

 

It's important also to remember that having an additional soundchip was absolutely part of GCCs design and plan for execution. The TIA was there for backwards compatibility, but they expected that a lot of games would include an on-cartridge sound chip, with Ball Blazer being the proof of concept for that and GCC working on a low cost, high performance GUMBY chip.

 

The reasons why it was not included on the core system has been debated throughout the years ... lack of space, drove the costs higher, GCC wanted to have an additional revenue stream. It was likely all of the above.

 

It's also been debated as to whether it was a good idea to have this design. I do suggest that it wasn't unheard of as most NES games have MMC chips that give the NES more capabilities than the stock NES.

 

Where this fell apart is the Tramiels didn't execute on this idea except one other time with Commando.

Share this post


Link to post
Share on other sites

 

Wow this is an old, old thread.

 

It's important also to remember that having an additional soundchip was absolutely part of GCCs design and plan for execution. The TIA was there for backwards compatibility, but they expected that a lot of games would include an on-cartridge sound chip, with Ball Blazer being the proof of concept for that and GCC working on a low cost, high performance GUMBY chip.

The reasons why it was not included on the core system has been debated throughout the years ... lack of space, drove the costs higher, GCC wanted to have an additional revenue stream. It was likely all of the above.

 

It's also been debated as to whether it was a good idea to have this design. I do suggest that it wasn't unheard of as most NES games have MMC chips that give the NES more capabilities than the stock NES.

 

Where this fell apart is the Tramiels didn't execute on this idea except one other time with Commando.

 

And if the 7800 had sold better then most games would have included the POKEY and poor sound wouldn't have been an issue...

 

I thought that the 7800 used the same audio as the 2600 for the sake of backwards compatibility. I could be wrong on that.

  • Like 1

Share this post


Link to post
Share on other sites

 

And if the 7800 had sold better then most games would have included the POKEY and poor sound wouldn't have been an issue...

 

I thought that the 7800 used the same audio as the 2600 for the sake of backwards compatibility. I could be wrong on that.

And the 7800 likely would have sold better if they could have gotten their hands on better titles, but because Nintendo locked up nearly all of the 3rd party development houses in questionable exclusivity contracts....

 

Hardware-wise, any one of the 3 contemporary consoles of that era (7800, NES, SMS) had a reasonable shot at cornering the market with smart design and investment. They all had their strengths and weaknesses. In the end - Atari invested too little internally in the console, and were all but shut out externally from 3rd parties helping sell their console.

Share this post


Link to post
Share on other sites

I still think people could have got around that. Look what a lot of them did like Konami making Ultra. One of these third party's could have made a third or even forth company if they wanted too to put games on the other systems. But even so atari them selves had tengen so why didn't they put out any of the games on their own system. Look at all the sega games Atari put on the NES yet none for your own system.

Edited by maxdrive
  • Like 1

Share this post


Link to post
Share on other sites

. But even so atari them selves had tengen so why didn't they put out any of the games on their own system. Look at all the sega games Atari put on the NES yet none for your own system.

Remember that at this point, Atari was two separate companies. There's Atari Crop, which was the Tramiel company with the computers and consoles, and Atari Games, which was the arcade company, and who owned Tengen.

  • Like 3

Share this post


Link to post
Share on other sites

But weren't they still together in some way you think that would be part of it

No, Atari Games and Atari Corp were totally separate companies. They did not seem to interact with each other until 1989 or 1990.

  • Like 4

Share this post


Link to post
Share on other sites

 

Wow this is an old, old thread.

 

It's important also to remember that having an additional soundchip was absolutely part of GCCs design and plan for execution. The TIA was there for backwards compatibility, but they expected that a lot of games would include an on-cartridge sound chip, with Ball Blazer being the proof of concept for that and GCC working on a low cost, high performance GUMBY chip.

The reasons why it was not included on the core system has been debated throughout the years ... lack of space, drove the costs higher, GCC wanted to have an additional revenue stream. It was likely all of the above.

 

It's also been debated as to whether it was a good idea to have this design. I do suggest that it wasn't unheard of as most NES games have MMC chips that give the NES more capabilities than the stock NES.

 

Where this fell apart is the Tramiels didn't execute on this idea except one other time with Commando.

 

Yeah, the NES did have the MMC chips but there is something people tend to over look about the NES when making these comparisons. Firstly, it has been stated, no less than by Shigeru Miyamoto himself, that the zenith for games making full use of stock hardware on the NES is Super Mario Bros. Secondly, you don't need mapper chips to get all of the music that you hear on North American and Pal releases. All those sounds and music that you hear are produced directly by the 2a03 CPU.

 

What I don't get is why it never occurred to GCE to simply run the 7800 game sounds and music through the 6502 like the Famicom did? I mean they had the specs and access to prototype units for the Famicom through thier contacts at Warner/Atari. They knew that the Famicom's solution to music and sound was through customizing the 6502. It would have allowed Atari to keep the TIA chip and at the same time would have eliminated any sort of need for the POKEY chip. It would have given the 7800 much more versatility out of the box than having a dev buy Pokey chips from Atari or whatever to get full use of the 7800's sound capabilities.

Edited by empsolo

Share this post


Link to post
Share on other sites

 

Yeah, the NES did have the MMC chips but there is something people tend to over look about the NES when making these comparisons. Firstly, it has been stated, no less than by Shigeru Miyamoto himself, that the zenith for games making full use of stock hardware on the NES is Super Mario Bros. Secondly, you don't need mapper chips to get all of the music that you hear on North American and Pal releases. All those sounds and music that you hear are produced directly by the 2a03 CPU.

 

What I don't get is why it never occurred to GCE to simply run the 7800 game sounds and music through the 6502 like the Famicom did? I mean they had the specs and access to prototype units for the Famicom through thier contacts at Warner/Atari. They knew that the Famicom's solution to music and sound was through customizing the 6502. It would have allowed Atari to keep the TIA chip and at the same time would have eliminated any sort of need for the POKEY chip. It would have given the 7800 much more versatility out of the box than having a dev buy Pokey chips from Atari or whatever to get full use of the 7800's sound capabilities.

 

No one would ever dispute that the stock sound chip of the NES is a lot better than the stock sound chip of the 7800.

 

My point is that it's overlooked by many who gripe about the sound that GCCs intent from the start was always that 7800 games had the ability to use an additional sound chip on cartridge. It wasn't an afterthought. They included TIA for backwards compatibility (a design goal for the system) but also the technical ability to also have the system use an on-board sound chip. When the Tramiel takeover happened, they had Ballblazer completed showing this concept and were also in the middle of designing a successor to POKEY called GUMBY which was intended to be a low cost, high performance sound chip for use in 7800 cartridges.

 

Your point about following Nintendo's lead with an integrated processor/sound hardware is interesting. I wonder if they were concerned with timing as the 7800 was already well in development when the Famicom was brought to Atari. After all the NES was not a foregone licensing conclusion for Atari and sending GCC back to the drawing board to integrate the sound hardware might have delayed things further for the 7800 leaving Atari with no system to sell if the NES deal fell through and the 7800 was delayed. (5200 was discontinued)

Share this post


Link to post
Share on other sites

There was an early prototype of the 7800 that was done on single-sided PCB (i.e., traces only on one side.. and an insane amount of wire jumpers). I wonder if that was where "not enough room for a soundchip" started. On the actual 2-layer version, I think they could have made room for another chip.

 

It seems crazy to put a sound chip into every cartridge. I wonder if they would have considered integrating the audio, mapper, and game ROM into the same chip. Possible, but I don't know at what quantity that becomes practical.

 

I haven't programmed anything for the 7800, but have looked into it. I know the NES inside and out. On a technical level, the NES just stomps it, mostly due to the PPU being generally more autonomous and having it's own memory bus brought to the cartridge. While on the 7800, the graphics are more software-controlled, it has some flexibility but it comes at a high cost of CPU time. Pretty much the 7800 can display things that would be really hard to do on NES, but overall it can't keep up with the NES. If you could put a CPU in a 7800 cartridge that runs the game, while the 6502 handles MARIA and other I/O, then the 7800 would definitely be more competitive with the NES.

 

On NES, mappers and the various MMC chips can add a lot of capability, but it's something like >60% of the NES library where the mapper is dead simple, they only bankswitch 16kB or 32kB program pages, and big 4kB pages (that's the full set of 256 tiles), if it pages graphics at all. That includes tons of games like Megaman 1&2, Castlevania, Contra, Zelda 1&2, etc.

 

Would be fun to make a new game and/or cartridge for 7800, I just don't have enough time for new projects.

Share this post


Link to post
Share on other sites
If you could put a CPU in a 7800 cartridge that runs the game, while the 6502 handles MARIA and other I/O, then the 7800 would definitely be more competitive with the NES.

 

Pretty sure that's one of the reasons why the clock line goes out to the cartridge - so a cpu or other chip go on there. Of course, being able to do something, and being able to do something economically are two entirely different beasts.

  • Like 3

Share this post


Link to post
Share on other sites

Join the conversation

You can post now and register later. If you have an account, sign in now to post with your account.

Guest
Reply to this topic...

×   Pasted as rich text.   Paste as plain text instead

  Only 75 emoji are allowed.

×   Your link has been automatically embedded.   Display as a link instead

×   Your previous content has been restored.   Clear editor

×   You cannot paste images directly. Upload or insert images from URL.

Loading...

  • Recently Browsing   0 members

    No registered users viewing this page.

×
×
  • Create New...