Atari 8bit graphics rules

[Atari-Jess]

Because I am too lazy to read a book, or a webpage, and, that I am not needing this for exact purposes (I am looking to get a correct look for something)

 

what are the rules for full screen graphics on the 8bit.

 

Now, I've got the right colour pallette, but I need to know, is there some sort of limit for colours? Is there a limit of colour per line?

 

If I made a graphic in the proper resolution, with the right pallete, using the maximum amount of colours I can, what am I not doing correct?

 

my resolution: 320x192, converting any image to the right pallete and that resolution.

 

appreciated.

[ZylonBane]

The first rule of Atari 8bit graphics is that you don't talk about Atari 8bit graphics.

[Heaven/TQA]

320x192... well... in this mode you don't need a pallette... as its highres...

 

check out g2f.atari8.info

[Atari-Jess]

I was looking at that, but I can't seem to load a bitmap into the program properly.

 

I am not trying to DRAW atari graphics or graphics FOR the atari, just making drawings that follow the rules for the atari 8bits

[emkay]

I was looking at that, but I can't seem to load a bitmap into the program properly.

 

I am not trying to DRAW atari graphics or graphics FOR the atari, just making drawings that follow the rules for the atari 8bits

900369[/snapback]

 

 

The best solution for this IS G2F... Drawing with the restrictions of the A8!

[Foebane]

Restrictions? WHAT restrictions!? ROFLMAO!

 

J/K

 

Well, yes, there are restrictions, but I'd like to know how the artist responsible for this piece did it:

(Apologies, but the Simpsons examples in the gallery on that website are fairly rude, this was the least offensive)

 

Now, I know this is high-res, and that it is usually monochrome, but that by judicious use of sprites and copper-style effects you can add colour, but I've never seen such fine examples of the technique.

 

I suppose this example uses sprites that fit the various coloured outlines of the picture, and that the colours of some sprites change half-way down the screen, but what about the resolution? I'm surprised it's so... high. Is there sprite multiplexing in use here?

 

If that program on the frontpage of the website generated all of those pictures, then I have a newfound admiration for what standard A8 graphics are capable of.

 

EDIT: Oh, I see now, the background and the 'yellow' skin are the original colours, right?

Edited July 28, 2005 by Foebane

[Atari-Jess]

The best solution for this IS G2F... Drawing with the restrictions of the A8!

900385[/snapback]

 

Well I can't quite import graphics properly into it, they always end up shifted oddly and strange colours.

 

again, I'm not trying to DRAW for the Atari, just convert other graphics for the LOOK of an Atari.

 

If I made an image like this:

 

 

It is 320 x 192, using 256 colours chosen by the .act palette file that comes with graph2fnt but I have the dithering to 100%.

 

it would seem to only use colours that the 8bits could generate (the proper 16 colours in 16 intensities) and in the maximum resolution.

 

But would that image be possible exactly as I have shown there?

in bitmap format it is 61kb (and 27 as a gif) is that image too big to be displayed

on the screen as a static image? can an image that uses almost the ENTIRE ram

of the system be displayed?

 

some consoles only allow a specific amount of colours on a scan line if I had some sort of crazy rainbow setup I could in theory put every colour on the pallete on every single line, does the hardware prevent me from that theoretical image?

 

And for comparison, here is that same bunny image with NO dithering what so ever

Edited July 28, 2005 by Atari-Jess

[danwinslow]

You can't do what you want to do. There are not enough colors available. There is not enough memory available. There is not enough resolution available. This is an eight bit machine from 25 years ago.

Edited July 28, 2005 by danwinslow

[emkay]

A solution for simply importing such graphics is "Interlace"....

JPEGVIEW handles this....

 

http://rjespino.tripod.com/8bit/a8jdpeg/gallery.html

[Atari-Jess]

You can't do what you want to do. There are not enough colors available. There is not enough memory available. There is not enough resolution available. This is an eight bit machine from 25 years ago.

900434[/snapback]

 

 

What I want to do IS possible, you just aren't being any help.

 

Colours can be lessened, Images can be less-dithered, resolutions can be made smaller!

 

I was not asking to do what I just displayed, I was asking what I needed to do to create an image that WOULD be displayable (if I had wanted to, which I don't) on the 8bit (without drawing it myself.)

Edited July 28, 2005 by Atari-Jess

[Atari-Jess]

A solution for simply importing such graphics is "Interlace"....

JPEGVIEW handles this....

 

http://rjespino.tripod.com/8bit/a8jdpeg/gallery.html

900436[/snapback]

 

This partially helps, this shows me that I can make images in those resolutions in greyscale.

 

So this does explain my resolution question. but not the colour

 

(and as a note to everyone:...)

 

I am not trying to load ANYTHING to an 8bit computer I am merely trying to create images that are the as exact quality as I can (following any specific rules for colour images) for the 8bit

 

For example, that same bunny image AGAIN can simply be made in any number of colours in the proper pallette.

 

Such as this 32 colour image of the bunny.

 

 

Still looks pretty good.

 

but does it need a border to properly load otherwise some colours mess up?

does a full screen image need to be under, say 32kb in bitmap'd mode to work

 

(IN THEORY?)

 

Im seeing this so far:

 

Technical details

CpegView has 3 different display modes:

 

# 80x200 in 256 colours: 16 colours x 16 levels of grey (APAC)

# 160x200 in 64 colours: 16 colours x 4 levels of grey (C15)

# 320x200 in 32 colours: 16 colours x 2 levels of grey (C8)

Edited July 28, 2005 by Atari-Jess

[Atari-Jess]

Okay, from what I see, using that jpeg view program, I can make an image, in that proper resolution include 16 colours of my choosing from the pallete, and add another 16, but adjust it that pallete any number of shades brighter or darker as long as its only brightness that changes thus giving me 32. and dithering won't make a difference if its a bitmap since it ends up just being ~62k file once its decompressed to a bitmap anyway.

 

If I am wrong please correct me.

Edited July 28, 2005 by Atari-Jess

[danwinslow]

You can't do what you want to do. There are not enough colors available. There is not enough memory available. There is not enough resolution available. This is an eight bit machine from 25 years ago.

900434[/snapback]

 

 

What I want to do IS possible, you just aren't being any help.

 

Colours can be lessened, Images can be less-dithered, resolutions can be made smaller!

 

I was not asking to do what I just displayed, I was asking what I needed to do to create an image that WOULD be displayable (if I had wanted to, which I don't) on the 8bit (without drawing it myself.)

900441[/snapback]

 

Well, excuse me. See this part here ?

 

But would that image be possible exactly as I have shown there?

in bitmap format it is 61kb (and 27 as a gif) is that image too big to be displayed

on the screen as a static image? can an image that uses almost the ENTIRE ram

of the system be displayed?

 

 

No, its not possible exactly as you showed there. No, you can't display a picture as big as the entire RAM space. No, you can't get any sort of decent 256 color dithering. Next time you get huffy you might consider re-reading your own material.

 

*especially* when you started off by telling us you are too lazy to go find out yourself.

 

Because I am too lazy to read a book, or a webpage, and, that I am not needing this for exact purposes (I am looking to get a correct look for something)

Edited July 28, 2005 by danwinslow

[Atari-Jess]

I was too lazy, but then someone just sort of threw it at me, and it was all good.

 

You still were not being useful, and infact you've continued to prove my point about your usefulness. All you've done, is try to argue against my statement about you. (but you did answer my question about the ram, so thanks)

 

What you did was go off and say "nope, can't be done, forget it, 8bits too old" and even then, if you look you CAN get 256 colours if you're willing to sacrifice resolution.

 

You could have suggested my alternatives. Which you didn't.

 

I'm not getting huffy, and yes a lot of my typing seems to say one thing then the other

 

"again, I'm not trying to DRAW for the Atari, just convert other graphics for the LOOK of an Atari."

 

Which would mean to say that I am going to be very flexible in doing a proper conversion. Which I am.

Edited July 28, 2005 by Atari-Jess

[Heaven/TQA]

aaaarg....

 

 

if you want to start...

 

160x200x4

 

80x200x16 shades

 

80x200x9 colours

 

or

 

hip/tip modes 160x200x256

 

or

 

G2f...check out the example pics...

 

if you want to enhance your bunny pic...reduce it to f.e. 160x200x4, load it into g2f and then colour it and spice it up with all the g2f features (sprite overlay/underlay, rasterinterrupts etc...)

 

what else can i say?

[ZylonBane]

Guys, it's obvious that anything to do with interrupts, mode changes, character graphics, sprite overlays, et al, is just going to blow Atari-Jess's mind. So here-- 160x192, 4 colors. Deal with it.

[urborg]

You doing wrong because you take maximum Atari resolution available and whole atari palette, but you can't use it all in 8-bit Atari. There is no such graphic mode available there. Most popular mode was 160x192 in 4 colours. If you use this mode you will get something similar to those two images. First is made using dithering method of decreasing number of colours and the second is using nearest colour method.

 

 

But if You use G2F you can get fifth colour by converting graphic to chars. So You can something like that:

 

 

Then there is possibility to enchance this image even more using some tricks. For example changing colours in each scanline (with limitations of 4 or 5 colour per scan line) using interrupts or adding more colours by using sprites. G2F allow you to do this all things, but it is not that simple as it sounds.

Edited July 29, 2005 by urborg

[Foebane]

You could use PMG for the device and the hand, using those colours, etc.

 

Then use the top range of the interrupts for the background, changing to the rabbit colours for the middle, and then the white suit thing at the bottom.

 

Am I on the right track?

Edited July 29, 2005 by Foebane

[Fröhn]

What's the use of this discussion anyway? If he is too lazy to search the net, he is certainly too lazy to do good conversions of pictures, because there is some work involved to make them look ok and a hell lot of work to make them good.

[Atari-Jess]

Hello everyone,

 

Dear Fröhn, shh, I got the answers I needed, no need for further insults.

 

I'm not "too lazy" to do the conversions, but I'll get to laziness later...

 

The information I gathered from urborg (the most) and Heaven/TQA next are wonderfully helpful and solved my questions with examples and suggestions.

 

And ZylonBane? That hurts. I know full well what interrupts, mode changes, character graphics, sprite overlays are. I am and have always been a programmer first.

 

(just not a fancy one)

 

But again, you guys as you like to do want to go enlength about all the custom tricks that can be pulled out of the Atari.

 

Urborg has created the imagery that looks quite close as far as I could imagine

 

The reason I am asking for this is because I am working on something that I don't have an incredible amount of time to begin reading programmer journals, Just to get some pictures I am only using to improve the visual

effect of the end project.

 

So again Gentlemen, thank you, I have got the answers I was looking for!