Comparison of 8-bit Computers

[breathdeeply]

I recently bought a used 800XL with some classic cartridges...

 

One on One

Archon I

Rescue on Fractalus

Star Raiders (awesome!)

Pengo

Miner 2049er

Zone Ranger

Centipede

Galaxian

Qbert

 

and i've noticed that many of the games for the Atari have superior graphics/colors than the Commodore 64 that i've had for many years. I guess it's a give and take where the C64 has superior sound for many games and the Atari has superior graphics for many games.

 

Also, i've read a lot about Star Raiders on this board and finally got the chance to play it (after 20 years) and it's AWESOME! Just like the C64 has it's share of space/adventure games, the Atari has really surprised me and right now i'm addicted to Rescue on Fractalus and Star Raiders! It's the best of both worlds - I love all the classic systems now :!:

[DamageX]

Well... some folks don't like to make these comparisons because it can turn into a heated debate (A8 rulz!!1!, C64 5uck5!, etc.)

 

I like to put the specs side by side and see how these old and interesting designs measure up. I have an A8, C64, TI-99, IIGS, A2000, old Mac, PCs, and just got an MSX2 (might still have a Coleco ADAM around also). Every system has something going for it whether it is capability, simplicity, value, whatever.

[Allas]

Star raiders 2 and Rescue on Fractalus use real power of Antic/GTIA chip from Atari. I have Atari 800XL and a C128, always than I show these Atari versions, C64 users are surprised.

 

Maybe you must try with Mercenary is a more complex and interesting adventure (only I recomend download the manual first).

 

A more arcade space adventure will be found in Cosmic tunnels

[Dr. Van Thorp]

Well, the Atari and C-64 had very similar graphics capabilities. The Atari had more colors; the Commodore had (I think) a better system for mapping colors on the screen. I think that Commodore's sprite system was better, but I'm sure someone will disagree. Both machines have better graphics than the Apple II.

 

Has anyone made a web page comparing old eight-bit machines, with descriptions of how the graphics modes work?

[+MrFish]

One of the things to be noted about the Atari, when making comparisons, is that the vast majority of titles produced (games included) were made to be compatible with the older 400/800 series. These machines were limited to 48k of RAM and subsequently caused the capabilities of the XL/XE machines, which had a base RAM of 64k (same as the Commodore), to be choked by the marketing strategies of software manufacturers. This is a rarely talked about fact.

 

Just check the packaging of most Atari titles, and you'll see that the system requirements state that a minimum of 48k is needed. Although this may seem minimal, this extra 16k which was available on the XL/XE machines could have been used for much in the way of enhancements such as: more complex music, better graphics, more intelligent A.I, etc...

 

This marketing strategy was a good Idea from the standpoint of compatibility with the larger market, but was not a very good one for those who purchased the second-generation machines and expected programs/games that showed what these machines could really do. What the XE/XL buyers ended up getting was a more powerful machine with few software titles to take advantage of the capabilities.

 

This is why many programmers and fans of the A8's are frustrated when arguing for their platform. The capabilities are there, but were only marginally exploited (in most cases). This doesn't mean that good titles weren't produced, but only that many titles could have been better.

 

The Commodores had no problem with this, as their base machine was 64k. Only later, when it was realized that better programs (mainly games to compete with the Nintendo revolution) were needed, did the software development strategies lean towards the higher end A8's. This was short lived, as it was too late for Atari, which hadn't the resources, and too late for the XL/XE's which were feeling their age.

 

Having said all of that, their are many great titles for the A8's, and the capabilities are always there for any that are willing to undertake the challenge to exploit them.

 

I would also like to see side-by-side comparison of the A8 and C64 that Dr. Van Thorp has requested.

 

They are both great machines that deserve attention for being milestones in the evolution of both computing and gaming.

Edited February 25, 2006 by MrFish

[Fröhn]

I recently bought a used 800XL with some classic cartridges...

 

[...]

 

and i've noticed that many of the games for the Atari have superior graphics/colors than the Commodore 64 that i've had for many years.  I guess it's a give and take where the C64 has superior sound for many games and the Atari has superior graphics for many games.

No wonder, those games were written for the Atari in the first place and are suited for the Ataris capabilities. It's the nature of ports that they're usually worse than the original, sometimes because the system where the games are ported to doesn't suit the game as well as the original platform (like Rescue on Fractalus) or be it that the port was done in no time with no budget.

 

While Rescue on Fractalus will always perform better on an 800 XL than on C64, I doubt anyone would be able to do a good port of Turrican from C64 to 800 XL.

[emkay]

 

While Rescue on Fractalus will always perform better on an 800 XL than on C64, I doubt anyone would be able to do a good port of Turrican from C64 to 800 XL.

949232[/snapback]

 

That's mainly, because the A8 has no Manfred Trenz around

 

So while the Jump'n'Run parts of the game will always look reduced from 16 to 8 available colours per scanline; the flying part would give more real action on the A8.

[Fröhn]

the flying part would give more real action on the A8.

? It would? How can it run faster than 50 fps?

[breathdeeply]

I also noticed that there is a MUCH larger library of cartridge based games for the Atari than Commodore (Rescue on Fractalus only comes on disk for the C64 ). With the exception of the text adventure games which I load up on occasion, I generally avoid disk based games these days because of the load times + carts last forever with only a bit of care

 

I agree, each system has their own pluses and minuses. Now I can understand how Star Raiders was the hottest thing in computers/video gaming in the early 80's due to its originality, depth, and playability - and at only 16K :!:

It proved 25 years ago that megabytes of memory doesn't necessarily make a good game, innovation does.

 

As a born-again retro-gamer, I think it would be pretty cool if there was a compilation of text adventure games on a cartridge (for example, the Infocom Adventure or Sci-Fi compilation) and just save your place on disk or cassette.

 

Also, i'd love to see Dino Eggs on cartridge for the Atari!

[Allas]

There are several reason why Atari was not a success computer at the 85s:

 

- Atari was a expensive machine

- Techniques programming for awesome graphics are very unique. Others machines use another concepts like C64, Spectrum, Amstrad, etc. This result in low quality portings for this machine, and viceversa.

- Due to costs production, Atari didn't add new extended hardware (like GTIA in 800) for XL and XE series. Needs a enhanced sprites engine and maybe a few Antics modes too. (with VRAM velocities in 84 it could be posible, more colors, more resolution like Enterprise)

- Atari compatibility machines was a good idea (in a 8bit chaos compatibility), without this, Atari could had been disappeared before 1984.

- Synthetizer music fever in the 85s

 

 

Who are the guilty:

 

Jack Tramiel : put too much cheap price to C64 even below cost production. Result: C64 is a low quality manufacturing computer, plenty units not working fine, i remember units that never working. This put the Commodore in financial problems, but C64 sells very well and got the market superiority. Otherwise, another 8-bit computers failed for low sales like Atari.

 

Ironically, Jack Tramiel made the last Atari model series XE.

[+remowilliams]

I prefer to play almost all of the "golden age" classics on the A8 series. Most of the titles that exist on both platforms were far better on the A8 for me. Plus I don't have the time to wait hours to load Blue Max on the C64

 

Though there are many titles that are excellent on the C64 I enjoy - usually games that were made after all the software houses abandoned the A8.

 

They're cheap, get 'em all I say!

[supercat]

I also noticed that there is a MUCH larger library of cartridge based games for the Atari than Commodore (Rescue on Fractalus only comes on disk for the C64  ).  With the exception of the text adventure games which I load up on occasion, I generally avoid disk based games these days because of the load times + carts last forever with only a bit of care   

949256[/snapback]

 

Did cartridge games on the Atari add code space outside the machine's native memory capacity (i.e. would you get 16K ROM plus 48K RAM)? If so, that would explain why many A800 games came out on cartridge. While it would be possible for a Commodore 64 cartridge to increase the total addressable space, very few actually did so (I can't think of any offhand).

 

Cartridges had a substantial manufacturing price premium. If this meant they could do things disk/tape games couldn't, it was worth it. If not, why bother?

[ijor]

memory capacity (i.e. would you get 16K ROM plus 48K RAM)? 

 

There were many computers out there with less than 48k ram; the 400 and 600XL come with 16K ram only. You couldn't run most games on those systems on tape or disk.

[Foebane]

memory capacity (i.e. would you get 16K ROM plus 48K RAM)? 

 

There were many computers out there with less than 48k ram; the 400 and 600XL come with 16K ram only. You couldn't run most games on those systems on tape or disk.

949353[/snapback]

 

But I bet you could on Carts, right?

[Gunstar]

the flying part would give more real action on the A8.

? It would? How can it run faster than 50 fps?

949252[/snapback]

What game on the Atari or C64 runs at 50fps? But theoretically, an NTSC Atari 8-bit or C64 (though I highly doubt either are fast enough anyway, usually they can manage 25/30fps, respectively, on 50hz/60hz machines) could do 60fps becuase if the program you are refering to running at 50fps is on a PAL machine with the refresh rate of 50hz as opposed to 60hz refresh rate of NTSC video

[Gunstar]

memory capacity (i.e. would you get 16K ROM plus 48K RAM)? 

 

There were many computers out there with less than 48k ram; the 400 and 600XL come with 16K ram only. You couldn't run most games on those systems on tape or disk.

949353[/snapback]

 

But I bet you could on Carts, right?

949390[/snapback]

 

Right. Most of the classsic games came out at the time of the 400/800 and the original standard cart was 16k, they continued with 16k cartridges for the most part into the XL line for compatibility with the 400/600XL. Though there were a few games that used more than 16k, up to 48k or 64k, but they used 16k bank switching and were still compatible with the 16k machines. By the time the XE cartridges came out, they were finally using 32-128k or better cartridges some of which were still compatible with the 800 with 48k, but many required at least 64k of the 800XL/1200XL or 65/130XE(128K). Though even the later cartridges that were 128k or more still used a 64k banking technique so they are compatible with any XL/XE with at least 64k, but not the 400/800/600XL unless the 600XL is upgraded to 64k, but it still leaves out the original 400/800 which both could only go to 48k for full compatibility. By the time the XE cartridges came out though, and many of the newer games that use the full potential of the Atari 8-bit(on any media, cart/tape/disk), the C64 had the Atari 8-bit line down for the count. (this was not JUST do to 16k cartridges though, but more support and marketing.

Edited October 17, 2005 by Gunstar

[DamageX]

Carts have a few advantages. They work on any A8 without extra hardware (like tape player or disk drive), there is no loading time, and they're more durable. A cart normally does cover up any RAM that is in the same address range though.

 

For comparing Atari vs. C64 it would help if a real C64 hacker could chip in. I only wrote a simple demo on a C64 once, here is some info though:

-resolution is 320x200 with 1 bit per pixel or 160x200 with 2bpp

-the screen can be either character-mapped with a size of 40x25 characters, or bit-mapped but with the data arranged in a somewhat strange manner

-16 available colors

-1000 bytes of screen memory where each byte specifies which character will appear (for text/character-mapped mode)

-you can change the address of screen memory but it has to be located on a 1K boundary

-1000 bytes of "color RAM" where each byte contains two 4-bit values which are colors that can appear at that location on the screen

-8 sprites. I think they were 8 bits wide with a fixed height (24?)

-scrolling of the entire screen up to 8 pixels in each direction

 

Beyond that there are of course some other details and raster effects to consider. Now for the Atari:

-programmable vertical screen size (usually 192 lines) and resolution (single or double line)

-horizontal resolution of 320x1bpp, 160x2bpp, 80x4bpp, 160x1bpp, 40 column text, 20 column text, etc. (as well as narrow and wide playfield modes)

-display list and screen data can be located almost anywhere

-scrolling can be selectively activated for each display list entry

-128 available colors (256 in GTIA luminance mode)

-5 players (8 bits wide and full height) or 4 players and 4 missles (2 bits wide)

 

I would say the C64's strengths are the additional sprites and the color RAM which allows for multicolor text and the like. In other areas the Atari is much more flexible, especially with the larger color palette.

 

The Apple computers didn't have sprites, scrolling, or multicolor text modes (not even the IIGS).

 

The TI9918 chip used in the TI-99, original MSX, and Coleco is similar to the C64 except with separate VRAM, a smaller screen (256 pixels wide) and more sprites. The MSX2 video chip is a much-improved upgrade which supports 256x212x8bpp, 512x212x4bpp, interlaced modes, and 512 available colors.

Edited October 17, 2005 by DamageX

[supercat]

-resolution is 320x200 with 1 bit per pixel or 160x200 with 2bpp

-the screen can be either character-mapped with a size of 40x25 characters, or bit-mapped but with the data arranged in a somewhat strange manner

 

The Commodore 64 has, depending upon exactly how you count, five modes:

1. 
    
    
   
2. Straight text mode--40 column text; each cell shows any of 256 characters with any of 16 foreground colors; all cells show a common background.
    
   
3. Extended-background mode--40 column text; each cell shows any of 64 characters with any of 16 foreground colors; each cell can independently use one of four background colors.
    
   
4. Multicolor text mode--40 column text; each cell shows any of 256 characters and is independently selectable to use either one of eight foreground colors and a common background (hires) or to use multicolor mode with one of eight foreground colors, the common background, and two other colors in common with other multicolor characters.
    
   
5. Hires graphics--320x200, with each 8x8 block having an independently-specified foreground and background color
    
   
6. Multicolor graphics--320x200, with each 8x8 block having three independently-specified colors plus a shared background color
    
   

-16 available colors

-1000 bytes of screen memory where each byte specifies which character will appear (for text/character-mapped mode)

-you can change the address of screen memory but it has to be located on a 1K boundary

Correct on all of these.

-1000 bytes of "color RAM" where each byte contains two 4-bit values which are colors that can appear at that location on the screen

The color memory is 1024 nybbles (the top four bits are not populated and always read 1's) and is not included in the 64K tally (incidentally, the VIC20 has 1024 nybbles of color memory, also not included in its 5K tally). The color memory specifies foreground color only, along with whether to use multicolor mode for a given character. It is not used in hires graphics mode.

-8 sprites. I think they were 8 bits wide with a fixed height (24?)

24x21 for single-color sprites; 12x21 (double-wide pixels) for multi-color sprites. Multicolor sprites have one 'individual' color plus two colors shared with other multicolor sprites. Sprites may be double-high or double-wide. Sprites may be reused vertically but a sprite must 'end' before it can be reused.

-scrolling of the entire screen up to 8 pixels in each direction

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With proper timing it is, of course, possible to scroll smoothly over larger distances. Being able to move the start of screen pointer more finely would have been helpful, but it's not possible.

 

Incidentally, it's also worth mentioning that the VIC-II chip has a 40-byte buffer; on the first scan line of each 8-pixel-high row, the VIC-II needs to make two memory fetches for each 8 pixels output (the first fetch gets the character and color data simultaneously ; the second gets the character shape data). During this time, the processor is stalled. On the remaining scan lines of the character row, this data is not refetched and thus the processor can run full speed. What's the memory-clocking situation on the 400/800?

[Shawn Jefferson]

Right. Most of the classsic games came out at the time of the 400/800 and the original standard cart was 16k, they continued with 16k cartridges for the most part into the XL line for compatibility with the 400/600XL. Though there were a few games that used more than 16k, up to 48k or 64k, but they used 16k bank switching and were still compatible with the 16k machines. By the time the XE cartridges came out, they were finally using 32-128k or better cartridges some of which were still compatible with the 800 with 48k, but many required at least 64k of the 800XL/1200XL or 65/130XE(128K). Though even the later cartridges that were 128k or more still used a 64k banking technique so they are compatible with any XL/XE with at least 64k, but not the 400/800/600XL unless the 600XL is upgraded to 64k, but it still leaves out the original 400/800 which both could only go to 48k for full compatibility.

 

A few details:

 

The cartridge banking space is the same in both models (400/800 and XL/XE), that is $8000-$BFFF, which is 16k. Some cartridges could take up only 8k of that space if they wanted to ($A000-$BFFF). The banking schemes of the cartridge itself could be quite varied, although they all had to live in the same address space. None of them could bank in more than 16k of their cartridge memory at any one time.

 

The only reason a cartridge would require a 64k machine is if the program uses space under the ROM. This is where the additional 16k of memory was in the XL/XE computer. Possibly this was a marketing thing and not an actual requirement of the software.

 

Compatability with the 16k machines had everything to do with how much RAM the program on the cartridge used. Some programs used very little, some quite a bit more (and that data had to be copied from cartridge to the RAM in the computer.)

 

By the time the XE cartridges came out though, and many of the newer games that use the full potential of the Atari 8-bit(on any media, cart/tape/disk), the C64 had the Atari 8-bit line down for the count. (this was not JUST do to 16k cartridges though, but more support and marketing.

 

It was certaintly a shame to see the A8 go down. All it needed was some upgrading in the form of an enhanced ANTIC/GTIA. Another four player/missiles would have been nice.

[Shannon]

I recently bought a used 800XL with some classic cartridges...

 

One on One

Archon I

Rescue on Fractalus

Star Raiders (awesome!)

Pengo

Miner 2049er

Zone Ranger

Centipede

Galaxian

Qbert

 

and i've noticed that many of the games for the Atari have superior graphics/colors than the Commodore 64 that i've had for many years.  I guess it's a give and take where the C64 has superior sound for many games and the Atari has superior graphics for many games. 

 

949095[/snapback]

 

Congrats. I've always felt the same way and enjoy alot of atari 8-bit titles than the C64 equivalent. That being said there still are great titles for the C64 as well. Just like any system the best usually cater to that systems strengths.

 

Dont give up on disk based games though. There are alot of goodies like MULE, lode runner, seven city's of gold, alternate reality (city/dungeon) and more!

[Fröhn]

What game on the Atari or C64 runs at 50fps?

Almost all games run at 50 fps on a C64 and from what i've seen this is also the case on Atari (jump'n'runs etc). Turrican, Katakis, Giana Sisters, IO, Armalyte, Uridium, Hawkeye etc etc. Even Speedball which runs at 25 fps on Amiga has a 50 fps rate on C64

 

24x21 for single-color sprites; 12x21 (double-wide pixels) for multi-color sprites.  Multicolor sprites have one 'individual' color plus two colors shared with other multicolor sprites.  Sprites may be double-high or double-wide.  Sprites may be reused vertically but a sprite must 'end' before it can be reused.

It's worth to mention that the sprites resolution is independent from the resolution of the used graphic mode and the resolution of the other sprites. Also, the sprite movement resolution is always 320x200, no matter what modes are chosen. Same for horizontal and vertical scrolling: A 160x200 gfx mode still has 320x200 scrolling resolution which makes scrolling quite smooth. And finally each sprite has an independent color.

 

With proper timing it is, of course, possible to scroll smoothly over larger distances.  Being able to move the start of screen pointer more finely would have been helpful, but it's not possible.

Ofcourse it's possible, but there is no dedicated register for that. You have to do some VIC-II trickery to set the screen pointer.

 

Incidentally, it's also worth mentioning that the VIC-II chip has a 40-byte buffer; on the first scan line of each 8-pixel-high row, the VIC-II needs to make two memory fetches for each 8 pixels output (the first fetch gets the character and color data simultaneously ; the second gets the character shape data).  During this time, the processor is stalled.  On the remaining scan lines of the character row, this data is not refetched and thus the processor can run full speed.  What's the memory-clocking situation on the 400/800?

Atari has the same in character mode: on a 40x25 textmode the cpu will be stopped for 40 cycles every 8th rasterline. Bitmap modes on Atari don't have this cpu stopping due to no color cell data to be fetched.

[Rybags]

Most original cartridges were 8K. There were even some (like Gridrunner) that were 4K. Many early carts also had to run on 8K of RAM.

 

re: processor halting. In 40 character modes, the processor loses 80 cycles due to character and character set DMA from ANTIC. A good programming technique is to not use WSYNC but to have NOPs instead. DLI routines usually receive control about 2/3rds the way through the previous scanline. On the C64, the VIC-II chip and the memory are clocked at 2x the processor speed, which means less cycles are lost due to DMA, except for the first line of text rows, and some cycles where sprites are displayed.

 

re: framerates. 50/60 FPS is entirely possible on the Atari and '64. In most cases, actual screen data only needs to be totally redrawn 5-10 times per second.

[carmel_andrews]

Carts have a few advantages. They work on any A8 without extra hardware (like tape player or disk drive), there is no loading time, and they're more durable. A cart normally does cover up any RAM that is in the same address range though.

 

For comparing Atari vs. C64 it would help if a real C64 hacker could chip in. I only wrote a simple demo on a C64 once, here is some info though:

-resolution is 320x200 with 1 bit per pixel or 160x200 with 2bpp

-the screen can be either character-mapped with a size of 40x25 characters, or bit-mapped but with the data arranged in a somewhat strange manner

-16 available colors

-1000 bytes of screen memory where each byte specifies which character will appear (for text/character-mapped mode)

-you can change the address of screen memory but it has to be located on a 1K boundary

-1000 bytes of "color RAM" where each byte contains two 4-bit values which are colors that can appear at that location on the screen

-8 sprites. I think they were 8 bits wide with a fixed height (24?)

-scrolling of the entire screen up to 8 pixels in each direction

 

Beyond that there are of course some other details and raster effects to consider. Now for the Atari:

-programmable vertical screen size (usually 192 lines) and resolution (single or double line)

-horizontal resolution of 320x1bpp, 160x2bpp, 80x4bpp, 160x1bpp, 40 column text, 20 column text, etc. (as well as narrow and wide playfield modes)

-display list and screen data can be located almost anywhere

-scrolling can be selectively activated for each display list entry

-128 available colors (256 in GTIA luminance mode)

-5 players (8 bits wide and full height) or 4 players and 4 missles (2 bits wide)

 

I would say the C64's strengths are the additional sprites and the color RAM which allows for multicolor text and the like. In other areas the Atari is much more flexible, especially with the larger color palette.

 

The Apple computers didn't have sprites, scrolling, or multicolor text modes (not even the IIGS).

 

The TI9918 chip used in the TI-99, original MSX, and Coleco is similar to the C64 except with separate VRAM, a smaller screen (256 pixels wide) and more sprites. The MSX2 video chip is a much-improved upgrade which supports 256x212x8bpp, 512x212x4bpp, interlaced modes, and 512 available colors.

949564[/snapback]

 

 

 

 

I read somewhere that Apple (during their 8bit days) did a deal with TI to using their sprite/graphics chip as an upgrade option for apple 8bits

[sack-c0s]

the c64 description seems right to me, although the scrolling limitations can be overcome with hacks likes VSP and FLD and the colour limitations can be surpassed using FLI. it's all to do with how the scroll registers work at a hardware level - they trigger and start a new line of character blocks *precisely* when the Y scroll bits match the lower 3 bits of the line number, so you can delay them (across a line for VSP, or down lines for FLD) or force them to happen every line so each lines has its own colour data (for FLI).

 

but pretty much right, yeah.

[Fröhn]

re:  framerates.  50/60 FPS is entirely possible on the Atari and '64.  In most cases, actual screen data only needs to be totally redrawn 5-10 times per second.

Screen data can be redrawn every frame because it's only 1000 bytes in character mode anyway. And even the 2000 bytes if you also move color data is not too much.