Atari v Commodore

[atariksi]

...

for non coders... imagine we want to scroll gfx horizontal every 2nd frame one pixel to the left... on A8 we would skip every 2nd frame the scrolling to achieve that. On c64 we could simply do scrolling as normal because the scrolling speed is the same...so after several frames both A8 and c64 reach the same point in the gfx but definitly the c64 has scrolled "smooth" while A8 not.

 

No, you would need to do data copies after every 4 color clocks on C64 whereas on Atari you have to deal with double buffering every other pixel scroll. And atari would have the extra speed in doing its manipulations of the buffers which can be optimized to lines if the entire display doesn't need to be horizontally scrolled. I don't see how c64 is smoother. And for scrolling by 1 color clock, Atari wins hands down-- faster speed to change the LMS pointers and no data copying involved.

[atariksi]

...

The hardware in the 64 is 8 registers worth of sprites. To show more than 8 sprites on screen

you HAVE to reuse the sprites by quickly moving them. There will never be more than 8 sprites

on screen physically with the C=64. Its an illusion just like with the player missiles of the A8.

You misunderstood how it works. If you multiplex C64 sprites, there really are more than 8 on a frame. A frame is not display "at once" but build up from rasterlines which are drawn from top to bottom. If you have a sprite at Y-position 50 and switch the Y-position to 150 at rasterline 100, the sprite will be displayed again on the very same frame.

 

The difference is the players can have the full height of the screen for images.

You can easily multiplex sprites to full height on C64. The C64 sprite logic is very multiplexing friendly. For example there are gfx modes which use a fullscreen sprite layer to enhance color depth.

 

Ahm, you forget that overscan eats up CPU cycles to limit your C64 multiplexer as well as bad scanlines as well as raster line interrupt overhead as well as all the cycles required to reuse sprite registers for vertical multiplexing. So if you are enhancing an image with sprite overlays, expect every 20 or so lines to see no enhancements (glitch depending on image). And if you just want to cover the screen with sprites (including overscan on vertical side) you can do it in BASIC w/o any interrupts or CPU cycles or RAM usage and have greater control than C64 on priority:

 

10 FOR T=53256 TO 53265:POKE T,255:NEXT T

20 POKE 53248,48:POKE 53249,80:POKE 53250,112:POKE 53251,144

30 POKE 53252,176:POKE 53253,184:POKE 53254,192:POKE 53255,200

40 POKE 704,32:POKE 705,64:POKE 706,128:POKE 707,16:POKE 623,32+1

 

Priority setting is:

 

POKE 623,32+1-- All Players on top of all playfields

POKE 623,32+2-- Players 0,1 on top of all playfields; players 2,3 below all playfields

POKE 623,32+0-- All Players at same depth as all playfields (ORs players with Playfields)

POKE 623,32+8-- Playfields 0,1 on top of all players; playfields 2,3 below all players

POKE 623,32+4-- All Playfields on top of all Players

 

Here it is again for the 3rd time. Now whoever thinks I dragged in overscan into the picture now is making false accusation.

[Crazyace]

Different screens show a different amount but memory addressing is supported up to 384 pixels without involving any scrolling. On LCDs you get the most visible output, but even 360*240 is superior. You are ready to point out that Atari has to use software to do half color clock but then C64 is also using software after every 4 color clocks. So they both are using a hardware/software combination but then Atari has hardware to do scroll on a per scanline basis as well as do it wide screen mode.

 

My point is that the Atari cannot scroll a multicolour screen by a single 320pixel interval. - The C64 can.

The Atari can scroll a monochrome screen by a single 320pixel interval with software though.

 

It's not really a hardware/software issue - more a missing capability

 

Do you actually get 384 pixels from an LCD screen? If not, then it's not a valid claim to make.

[atariksi]

Different screens show a different amount but memory addressing is supported up to 384 pixels without involving any scrolling. On LCDs you get the most visible output, but even 360*240 is superior. You are ready to point out that Atari has to use software to do half color clock but then C64 is also using software after every 4 color clocks. So they both are using a hardware/software combination but then Atari has hardware to do scroll on a per scanline basis as well as do it wide screen mode.

 

My point is that the Atari cannot scroll a multicolour screen by a single 320pixel interval. - The C64 can.

The Atari can scroll a monochrome screen by a single 320pixel interval with software though.

 

It's not really a hardware/software issue - more a missing capability

 

Do you actually get 384 pixels from an LCD screen? If not, then it's not a valid claim to make.

 

Atari scrolls the 320 pixel screen by software AND hardware. C64 scrolls the 320 pixel screen with hardware AND software unless you only want to scroll less than a byte. As far as being multicolor and scrolling by half a color clock, that's the point being addressed elsewhere. GPRIOR 0 and DLIs do get you colors in 320 mode although scrolling would be by one color clock. LMS pointers are missing hardware capability of C64 along with being able to hide data that's to be scrolled in. Half color clock scroll is do-able unlike 558ns accurate timers which are impossible to do via software on C64.

 

My LCD does 360*240 visually with 24 pixels missing. Try this:

 

POKE 82,0:POKE 559,35

 

and now type and count how many characters you see per line.

[Crazyace]

Different screens show a different amount but memory addressing is supported up to 384 pixels without involving any scrolling. On LCDs you get the most visible output, but even 360*240 is superior. You are ready to point out that Atari has to use software to do half color clock but then C64 is also using software after every 4 color clocks. So they both are using a hardware/software combination but then Atari has hardware to do scroll on a per scanline basis as well as do it wide screen mode.

 

My point is that the Atari cannot scroll a multicolour screen by a single 320pixel interval. - The C64 can.

The Atari can scroll a monochrome screen by a single 320pixel interval with software though.

 

It's not really a hardware/software issue - more a missing capability

 

Do you actually get 384 pixels from an LCD screen? If not, then it's not a valid claim to make.

 

Atari scrolls the 320 pixel screen by software AND hardware. C64 scrolls the 320 pixel screen with hardware AND software unless you only want to scroll less than a byte. As far as being multicolor and scrolling by half a color clock, that's the point being addressed elsewhere. GPRIOR 0 and DLIs do get you colors in 320 mode although scrolling would be by one color clock. LMS pointers are missing hardware capability of C64 along with being able to hide data that's to be scrolled in. Half color clock scroll is do-able unlike 558ns accurate timers which are impossible to do via software on C64.

 

My LCD does 360*240 visually with 24 pixels missing. Try this:

 

POKE 82,0:POKE 559,35

 

and now type and count how many characters you see per line.

 

I saw 43 - which is why I queried your 384 pixel statement.. ( On a C64 with the same screen and overscan I see more... )

 

As the GPRIOR 0 doesn't support scrolling in half colour clock amounts it is a limitation compared to the C64.

[atariksi]

Different screens show a different amount but memory addressing is supported up to 384 pixels without involving any scrolling. On LCDs you get the most visible output, but even 360*240 is superior. You are ready to point out that Atari has to use software to do half color clock but then C64 is also using software after every 4 color clocks. So they both are using a hardware/software combination but then Atari has hardware to do scroll on a per scanline basis as well as do it wide screen mode.

 

My point is that the Atari cannot scroll a multicolour screen by a single 320pixel interval. - The C64 can.

The Atari can scroll a monochrome screen by a single 320pixel interval with software though.

 

It's not really a hardware/software issue - more a missing capability

 

Do you actually get 384 pixels from an LCD screen? If not, then it's not a valid claim to make.

 

Atari scrolls the 320 pixel screen by software AND hardware. C64 scrolls the 320 pixel screen with hardware AND software unless you only want to scroll less than a byte. As far as being multicolor and scrolling by half a color clock, that's the point being addressed elsewhere. GPRIOR 0 and DLIs do get you colors in 320 mode although scrolling would be by one color clock. LMS pointers are missing hardware capability of C64 along with being able to hide data that's to be scrolled in. Half color clock scroll is do-able unlike 558ns accurate timers which are impossible to do via software on C64.

 

My LCD does 360*240 visually with 24 pixels missing. Try this:

 

POKE 82,0:POKE 559,35

 

and now type and count how many characters you see per line.

 

I saw 43 - which is why I queried your 384 pixel statement.. ( On a C64 with the same screen and overscan I see more... )

 

As the GPRIOR 0 doesn't support scrolling in half colour clock amounts it is a limitation compared to the C64.

 

I guess it depends on your monitor.

 

As far as half color clock not being in atari hardware, that's true but you have to see that once you are scrolling something that you want to maintain a certain speed, you have to select the slowest portion of your scroll which on the C64 is when you have to start copying data. On the Atari, it's when you flip buffers. And we're only talking horizontal scrolling. Vertical scrolling also has to be taken into account to determine which machine has superior scrolling hardware overall.

[potatohead]

Re: Not a valid claim to make.

 

If we are gonna talk details, like the 320 position scrolling (which I think is both cool and smooth, BTW), then we can talk overscan pixels with the same realism, right?

 

My PC capture card does 720x486. The Atari wide mode DMA is 48 bytes, with two bits of noise on the left. The resulting display is 384 - 2 for a total of 382 pixels of display. Let's say we lop a byte off the left and right, just to clean things up. That's 368 addressable and displayable pixels.

 

I'm not sure of the vertical overscan, but there are about 230 lines possible, minus sync and such. On the Atari, those are addressable and displayable as well.

 

Not sprites in the margin, but just plain old graphics mode (and you can pick which mode) pixels, such that the screen memory is a multiple of 48 bytes.

 

The bitmap scrolling is costly, and either takes a double buffer, or only moving objects during VBLANK, and given the time allowed, not that much can be moved within that time. Multiple character sets could be used also, but that's RAM hungry and likely not practical.

 

So, with Atari, it's 160 pixel (normal DMA, NTSC safe area) scrolling. No big deal.

 

C= gives us nice color positioning but a fixed display area. Atari is more coarse for positioning things, but does widescreen, full frame graphics, if desired.

 

Personally, I'll take the 160 pixel positioning (one color clock), wide screen and hardware scrolling any day! Costs less in a lot of scenarios, IMHO, and that leaves cycles for other tricks, or to allow for the full frame graphics. Advantage Atari in most scenarios.

Edited April 5, 2009 by potatohead

[Crazyace]

I guess it depends on your monitor.

 

As far as half color clock not being in atari hardware, that's true but you have to see that once you are scrolling something that you want to maintain a certain speed, you have to select the slowest portion of your scroll which on the C64 is when you have to start copying data. On the Atari, it's when you flip buffers. And we're only talking horizontal scrolling. Vertical scrolling also has to be taken into account to determine which machine has superior scrolling hardware overall.

 

I've never found that to be a problem in character mode on the c64 - double buffer the char memory, and copy the colour memory in vblank. It was very difficult to support in highres graphics mode though. The Atari LMS mechanism is just more elegant however.

Scrolling games on the C64 seem to do fine however - so at the end of the day I think it does have the superior scrolling hardware.

[Crazyace]

Re: Not a valid claim to make.

 

If we are gonna talk details, like the 320 position scrolling (which I think is both cool and smooth, BTW), then we can talk overscan pixels with the same realism, right?

 

My PC capture card does 720x486. The Atari wide mode DMA is 48 bytes, with two bits of noise on the left. The resulting display is 384 - 2 for a total of 382 pixels of display. Let's say we lop a byte off the left and right, just to clean things up. That's 368 addressable and displayable pixels.

 

I'm not sure of the vertical overscan, but there are about 230 lines possible, minus sync and such. On the Atari, those are addressable and displayable as well.

 

Not sprites in the margin, but just plain old graphics mode (and you can pick which mode) pixels, such that the screen memory is a multiple of 48 bytes.

 

The bitmap scrolling is costly, and either takes a double buffer, or only moving objects during VBLANK, and given the time allowed, not that much can be moved within that time. Multiple character sets could be used also, but that's RAM hungry and likely not practical.

 

So, with Atari, it's 160 pixel (normal DMA, NTSC safe area) scrolling. No big deal.

 

C= gives us nice color positioning but a fixed display area. Atari is more coarse for positioning things, but does widescreen, full frame graphics, if desired.

 

Personally, I'll take the 160 pixel positioning (one color clock), wide screen and hardware scrolling any day! Costs less in a lot of scenarios, IMHO, and that leaves cycles for other tricks, or to allow for the full frame graphics. Advantage Atari in most scenarios.

 

That's interesting - if you see 384 pixels of display what's the visual effect of smooth scrolling?

 

Doesn't the C64 give you full screen scrolling with no borders - It may be more difficult/involve sprites, but it's still possible?

[atariksi]

I guess it depends on your monitor.

 

As far as half color clock not being in atari hardware, that's true but you have to see that once you are scrolling something that you want to maintain a certain speed, you have to select the slowest portion of your scroll which on the C64 is when you have to start copying data. On the Atari, it's when you flip buffers. And we're only talking horizontal scrolling. Vertical scrolling also has to be taken into account to determine which machine has superior scrolling hardware overall.

 

I've never found that to be a problem in character mode on the c64 - double buffer the char memory, and copy the colour memory in vblank. It was very difficult to support in highres graphics mode though. The Atari LMS mechanism is just more elegant however.

Scrolling games on the C64 seem to do fine however - so at the end of the day I think it does have the superior scrolling hardware.

 

So when you have to double buffer stuff and employ software techniques, it's okay. But when atari does it, it's not a hardware feature. Bullcrap. Atari destroys the C64 in hardware scrolling horizontally and vertically. We're only been discussing 320 mode scrolling. Start to go through the 56+ graphics modes and look at it vertically and do up to 4096 bytes/scanline, and C64 doesn't stand a chance. Just because you have a half pixel color clock scroll with no other hardware support at all doesn't spell out to being superior to Atari. I already gave example of graphics 2 scrolling which would require a ton of CPU time on C64 to implement. LMS mechanism allows you to have vertical and horizontal scrolling of bytes whereas the 54276/54277 gives you 16 color clocks scroll horizontally and vertically which can also be used in GTIA modes. As I stated, C64 scrolling bitmaps was a superficial addition. Besides, the 4 color clocks that you can scroll with the 3 bits of scroll in X and Y, what else is there on the C64? And also, I forgot to mention that carving technique of showing hires colored graphics in 320 mode which when combined with double buffering allows you to scroll by half a color clock although as I stated don't find it that useful.

[atariksi]

Re: Not a valid claim to make.

 

If we are gonna talk details, like the 320 position scrolling (which I think is both cool and smooth, BTW), then we can talk overscan pixels with the same realism, right?

 

My PC capture card does 720x486. The Atari wide mode DMA is 48 bytes, with two bits of noise on the left. The resulting display is 384 - 2 for a total of 382 pixels of display. Let's say we lop a byte off the left and right, just to clean things up. That's 368 addressable and displayable pixels.

 

I'm not sure of the vertical overscan, but there are about 230 lines possible, minus sync and such. On the Atari, those are addressable and displayable as well.

 

Not sprites in the margin, but just plain old graphics mode (and you can pick which mode) pixels, such that the screen memory is a multiple of 48 bytes.

 

The bitmap scrolling is costly, and either takes a double buffer, or only moving objects during VBLANK, and given the time allowed, not that much can be moved within that time. Multiple character sets could be used also, but that's RAM hungry and likely not practical.

 

So, with Atari, it's 160 pixel (normal DMA, NTSC safe area) scrolling. No big deal.

 

C= gives us nice color positioning but a fixed display area. Atari is more coarse for positioning things, but does widescreen, full frame graphics, if desired.

 

Personally, I'll take the 160 pixel positioning (one color clock), wide screen and hardware scrolling any day! Costs less in a lot of scenarios, IMHO, and that leaves cycles for other tricks, or to allow for the full frame graphics. Advantage Atari in most scenarios.

 

That's interesting - if you see 384 pixels of display what's the visual effect of smooth scrolling?

 

Doesn't the C64 give you full screen scrolling with no borders - It may be more difficult/involve sprites, but it's still possible?

 

You can't be unsure about what C64 can do and be arguing that it's superior. I suggest you post a code that only uses hardware to scroll on C64 (overscan and w/o overscan) and someone here will post same for Atari. No moving of large blocks of data like lines/buffers.

[potatohead]

There is no way the C64 scrolling is superior. It's got 320 pixel positioning, and that's cool.

 

For everything else, there is a match on the Atari, plus a whole bunch of other scrolling options. ANTIC does lots of great stuff, not seen on other machines.

 

Re: what is the effect of smooth scrolling?

 

I don't know. Never tried it.

[Crazyace]

I guess it depends on your monitor.

 

As far as half color clock not being in atari hardware, that's true but you have to see that once you are scrolling something that you want to maintain a certain speed, you have to select the slowest portion of your scroll which on the C64 is when you have to start copying data. On the Atari, it's when you flip buffers. And we're only talking horizontal scrolling. Vertical scrolling also has to be taken into account to determine which machine has superior scrolling hardware overall.

 

I've never found that to be a problem in character mode on the c64 - double buffer the char memory, and copy the colour memory in vblank. It was very difficult to support in highres graphics mode though. The Atari LMS mechanism is just more elegant however.

Scrolling games on the C64 seem to do fine however - so at the end of the day I think it does have the superior scrolling hardware.

 

So when you have to double buffer stuff and employ software techniques, it's okay. But when atari does it, it's not a hardware feature. Bullcrap. Atari destroys the C64 in hardware scrolling horizontally and vertically. We're only been discussing 320 mode scrolling. Start to go through the 56+ graphics modes and look at it vertically and do up to 4096 bytes/scanline, and C64 doesn't stand a chance. Just because you have a half pixel color clock scroll with no other hardware support at all doesn't spell out to being superior to Atari. I already gave example of graphics 2 scrolling which would require a ton of CPU time on C64 to implement. LMS mechanism allows you to have vertical and horizontal scrolling of bytes whereas the 54276/54277 gives you 16 color clocks scroll horizontally and vertically which can also be used in GTIA modes. As I stated, C64 scrolling bitmaps was a superficial addition. Besides, the 4 color clocks that you can scroll with the 3 bits of scroll in X and Y, what else is there on the C64? And also, I forgot to mention that carving technique of showing hires colored graphics in 320 mode which when combined with double buffering allows you to scroll by half a color clock although as I stated don't find it that useful.

 

Both Atari and C64 involve software techniques - the LMS allows the Atari to handle scrolling big buffers more elegantly. The C64 has superior scroll resolution - You are spouting bullcrap if you think a software double buffer can give the same effect on the Atari.

 

You can't be unsure about what C64 can do and be arguing that it's superior. I suggest you post a code that only uses hardware to scroll on C64 (overscan and w/o overscan) and someone here will post same for Atari. No moving of large blocks of data like lines/buffers.

Why not move data? The C64 scrolling is based on moving data in character increments. I know how both systems work, so I dont feel the need to write some code - have a look at some of the c64 and atari demos ( or scrolling games ) if you want.

 

There is no way the C64 scrolling is superior. It's got 320 pixel positioning, and that's cool.

 

For everything else, there is a match on the Atari, plus a whole bunch of other scrolling options. ANTIC does lots of great stuff, not seen on other machines.

 

Re: what is the effect of smooth scrolling?

 

I don't know. Never tried it.

My point is that the 320 pixel positioning is why the c64 scrolling is superior. ( Antic does do a lot of cool stuff, and the overscan is nice in particular - pity it's difficult to get more than 240 lines in PAL )

[Allas]

There is no way the C64 scrolling is superior. It's got 320 pixel positioning, and that's cool.

 

For everything else, there is a match on the Atari, plus a whole bunch of other scrolling options. ANTIC does lots of great stuff, not seen on other machines.

 

Re: what is the effect of smooth scrolling?

 

I don't know. Never tried it.

 

C64 1/320 scroll with 1/50 updating is the same (on speed) with 2/320 Atari scroll with 2/50 updating. There is no problem with the 2/320 movement scroll on Atari, is enough. This is a example of Atari scrolling, 4 directions free, look what smooth it is, a little better on C64?... yes, but who cares, I never change the other features for 1/320 movement.

 

 

xscroll.zip

[Crazyace]

Yes - at the end of the day the difference between 1/160 scroll and 1/320 scroll is pretty minor - especially compared with other machines like the colecovision that never had any fine scroll capabilities at all.

[atariksi]

I guess it depends on your monitor.

 

As far as half color clock not being in atari hardware, that's true but you have to see that once you are scrolling something that you want to maintain a certain speed, you have to select the slowest portion of your scroll which on the C64 is when you have to start copying data. On the Atari, it's when you flip buffers. And we're only talking horizontal scrolling. Vertical scrolling also has to be taken into account to determine which machine has superior scrolling hardware overall.

 

I've never found that to be a problem in character mode on the c64 - double buffer the char memory, and copy the colour memory in vblank. It was very difficult to support in highres graphics mode though. The Atari LMS mechanism is just more elegant however.

Scrolling games on the C64 seem to do fine however - so at the end of the day I think it does have the superior scrolling hardware.

 

So when you have to double buffer stuff and employ software techniques, it's okay. But when atari does it, it's not a hardware feature. Bullcrap. Atari destroys the C64 in hardware scrolling horizontally and vertically. We're only been discussing 320 mode scrolling. Start to go through the 56+ graphics modes and look at it vertically and do up to 4096 bytes/scanline, and C64 doesn't stand a chance. Just because you have a half pixel color clock scroll with no other hardware support at all doesn't spell out to being superior to Atari. I already gave example of graphics 2 scrolling which would require a ton of CPU time on C64 to implement. LMS mechanism allows you to have vertical and horizontal scrolling of bytes whereas the 54276/54277 gives you 16 color clocks scroll horizontally and vertically which can also be used in GTIA modes. As I stated, C64 scrolling bitmaps was a superficial addition. Besides, the 4 color clocks that you can scroll with the 3 bits of scroll in X and Y, what else is there on the C64? And also, I forgot to mention that carving technique of showing hires colored graphics in 320 mode which when combined with double buffering allows you to scroll by half a color clock although as I stated don't find it that useful.

 

Both Atari and C64 involve software techniques - the LMS allows the Atari to handle scrolling big buffers more elegantly. The C64 has superior scroll resolution - You are spouting bullcrap if you think a software double buffer can give the same effect on the Atari.

...

 

Ahm, you stated previously C64 hardware scrolling is superior now you are stating that it has superior scroll resolution. Two different points. I agree it has one extra lsb of scroll resolution. But after you scroll 4 color clocks (3-bits), you have to resort to software-based copying whereas Atari has the LMS instruction which is hardware-based. Double buffer does achieve the same effect in 320*200 mode but not as fast as hardware unless data is static in which case it's as good as hardware.

 

>>You can't be unsure about what C64 can do and be arguing that it's superior. I suggest you post a code that only uses hardware to scroll on C64 (overscan and w/o overscan) and someone here will post same for Atari. No moving of large blocks of data like lines/buffers.

 

>Why not move data? The C64 scrolling is based on moving data in character increments. I know how both systems work, so I dont feel the need to write some code - have a look at some of the c64 and atari demos ( or scrolling games ) if you want.

 

Why not double buffer. We're not talking just about text scrolling but also bitmaps.

 

How do you implement a Graphics 1 or 2 scrolling screen without using tons of CPU cycles on the C64? You know like games like Riveraid which has a scrolling text mode line along with other scrolling.

[atariksi]

There is no way the C64 scrolling is superior. It's got 320 pixel positioning, and that's cool.

 

For everything else, there is a match on the Atari, plus a whole bunch of other scrolling options. ANTIC does lots of great stuff, not seen on other machines.

 

Re: what is the effect of smooth scrolling?

 

I don't know. Never tried it.

 

C64 1/320 scroll with 1/50 updating is the same (on speed) with 2/320 Atari scroll with 2/50 updating. There is no problem with the 2/320 movement scroll on Atari, is enough. This is a example of Atari scrolling, 4 directions free, look what smooth it is, a little better on C64?... yes, but who cares, I never change the other features for 1/320 movement.

 

 

xscroll.zip

 

Even with the 1/320 width scroll, it doesn't mean the overall scrolling hardware is superior on C64. On vertical side, Atari has the 4-bit VScrl hardware register along with the pointer to the data to scroll whereas C64 only has a VScrl register that's only 3-bits of scrolling. Also, I can scroll a particular mode line on Atari not the entire screen.

[atariksi]

Yes - at the end of the day the difference between 1/160 scroll and 1/320 scroll is pretty minor - especially compared with other machines like the colecovision that never had any fine scroll capabilities at all.

 

At least you're not as biased as some other C64 fanatics. I mean if I hook up a C64 with the audio/video cables mixed up or with interference noise, C64 biased person may say the noise you hear on the TV is the SID simulating crowd noise.

[Crazyace]

I think I'm actually more of an Atari fanatic if anything - I always used the 800 as my actual computer - ( Mac65 on cartridge ruled ) , and the c64 was only used as a target machine for cross development.

[potatohead]

Superior on one feature; namely positioning.

 

Superior over all, is NO contest. The points were made up-thread too. Atari can scroll big maps, little maps, horizontal, vertical, part of the screen, all of the screen and everything in-between with little CPU cost.

 

I like the fine positioning. It's a great feature, but it does not make the machine. Sorry

 

Add to that, nice, full overscan with essentially no tricks! Just ask for it, and the hardware delivers. And, with that overscan, it's easy to fill the whole display, no border. This adds nicely to the overall visual impact scrolling has. ...there is ZOOM on your newer TV's, I suppose!!

Edited April 5, 2009 by potatohead

[NRV]

There is no way the C64 scrolling is superior. It's got 320 pixel positioning, and that's cool.

 

For everything else, there is a match on the Atari, plus a whole bunch of other scrolling options. ANTIC does lots of great stuff, not seen on other machines.

 

Re: what is the effect of smooth scrolling?

 

I don't know. Never tried it.

 

C64 1/320 scroll with 1/50 updating is the same (on speed) with 2/320 Atari scroll with 2/50 updating. There is no problem with the 2/320 movement scroll on Atari, is enough. This is a example of Atari scrolling, 4 directions free, look what smooth it is, a little better on C64?... yes, but who cares, I never change the other features for 1/320 movement.

 

 

xscroll.zip

 

well, I try not to participate in these "yearly 100+ posts Atari vs CBM threads" but.. I never liked the colors of this thing in the emulator

 

here.. a better color version..

 

xscroll_v2.zip

 

 

one good thing about this scroll demo is that, "practically" it doesn't use cpu time, because of the nice tricks you can do with the display lists and the LMS's.. and they are 4x4 wide mode screens, of 48x28 characters (I don't remember why I don't used the fifth color).. also the foreground scrolls at a speed of 1 pixel per frame (horizontally and vertically), so the "background" scrolls at 1/2 pixel per frame (I know, I know.. one every two frames), but it doesn't look "bad"..

 

NRV

[Fröhn]

C64 needs a bit CPU overhead for scrolling, but A8 needs much much more for software sprites. In the end it's easier to code a scrolling game with sprites on C64 and that's the main reason why the C64 was the bigger market success.

[atariksi]

C64 needs a bit CPU overhead for scrolling, but A8 needs much much more for software sprites. In the end it's easier to code a scrolling game with sprites on C64 and that's the main reason why the C64 was the bigger market success.

 

Let's not speculate that better sprites horizontally was the reason for C64's bigger market coverage. If you can give some evidence for this, that would be a better approach.

 

You still have not explained how you can have a 160*240 sprite overlay and a bitmap behind it (or in front of it).

[Allas]

C64 needs a bit CPU overhead for scrolling, but A8 needs much much more for software sprites. In the end it's easier to code a scrolling game with sprites on C64 and that's the main reason why the C64 was the bigger market success.

 

No man, the best seller computer always be the cheaper computer. (And this, nothing to do with the quality, its a matter of marketing. Other way, C64 have a respectable quality for his time)

When i bought my C64, i knew has scroll hardware, but never suspect how powerful in comparison with Atari after many years after.

Even, other computers without scroll by hardware sold more games than Atari 8bit.

Edited April 6, 2009 by Allas

[Jetboot Jack]

it's easier to code a scrolling game with sprites on C64 and that's the main reason why the C64 was the bigger market success

 

NO it was not the hardware that made it popular - it was CHEAP and so it sold a lot, so there was huge demand for software, so people wrote lots for it, so it was attractive to more users, so it sold more etc...

 

Hardware performance NEVER drives the market place - otherwise we might have seen the Lynx being popular or the Megadrive dead quickly, but we didn't

 

sTeVE

Edited April 6, 2009 by Jetboot Jack