Any demo doing this?

[emkay]

Today I worked a bit with G2F again.

the result looks like this:

 

 

 

Vertical coloured pillars.... You see 80 colours per scanline.

[Allas]

Great!

 

Could you send the G2F file?

[twh/f2]

emkay,

 

could you please explain how you did it? what's the trick? can you confirm it to work on the real machine?

 

thx,

\twh

[xxl]

basic gr.9 and something like this?

 

---

sta wsync

lda #col1lum0

sta colbak

lda #col2lum0

sta colbak

lda #col3lum0

sta colbak

---

 

?

Edited October 8, 2007 by xxl

[Heaven/TQA]

it could be something as XXL said, changing background on the fly plus missles for transparency fx not the players.

 

Subject: PM-transparency etc. Szia Karesz, Yesterday I've checked the PM-transparency problem; Actually I wasn't correct when I wrote to you about this last year. Unfortunately the thing looks not so good; only the four missiles can be made transparent on a Gr.9 screen, and only if the GPRIOR register is set up as follows: - set GTIA mode to Gr.9 (bit 6=1, bit 7=0) - set priority to 0 (bits 0-3 = 0) - set 5th player mode for missiles (bit 4=1) so GPRIOR has to be set to $50. Then the color of the overlapping area will be: color of missiles ($d019/$02c7) logical-ORed with color of background ($d01a/$02c8). I'm not 100% sure about the truth of the last sentence, but this was my impression. I investigated these PM priority modes a couple of years ago, but I forgot to write down anywhere - the same as for the HIP effect;-) Anyway, I have some older routines that I wrote in Atmas II, which make use of this effect, so I'll check them out again, and make a small doc about it. But you can also check it yourself. BTW, I've also got Atari Intern, and it is one of my primary sources about the Atari... It has the most comprehensive description of the Atari hardware, which I have (I don't have the Atari Hardware Manual). Of course (?), even Atari Intern does not describe things like this priority-0/PM-transparency. (to say nothing of HIP, for example) But doesn't matter, we have left with enough new things to explore.;-) BTW, we should collect all the undocumented features of Atari in a document, (that is, make them *documented*;-) ) and put it online on a web page to allow everybody to profit from them. What's your opinion? As for the illegal opcodes on your page, I also have a couple of other docs describing these. There are some differences in the description of some of the opcodes, especially for the more complicated ones - probably because they can do really unpredictable things. (Known only for those, who know the inner workings of the 6502.) When I wrote MoniTOM, my monitor program back in 1992, I investigated most of these instructions, and included them in both the assembler and disassembler part of the program. (So you can use all the 256 instructions with it!) Now, that I'm redesigning MoniTOM, have another chance to clear this topic up - I plan to make redefinable even the mnemonic names of the opcodes by a config program - this can be useful because the same opcode is mentioned on 3-4 different names in different sources. To tell the truth, I've used only a couple of these instructions so far. Mostly in the boot blocks of Veronika and CE. But never in effects. I know, Sanyi used the LAX ($xx),Y instruction in the landscape routine in Joyride. (This is why it won't run on the 65816 turbo cards...;-) ) Do you know where I can find this APE-debugger you wrote about? Because I can't find anywhere. I'd be really interested in it as you can bet...;-) Have you managed to depack the mails? OK, that's all for now. Udv, Tamas 
______________________________________
Tamas Bene --- 

/__  __   __  _\
/  / /_|_ |   |__\  Software, Hungary
______________________________________

[Rybags]

But G2F uses character mode. The extra DMA on the first line makes such changes impossible.

 

And, playing around with Atari800Win+ it seems PMGs ignore their priority bits and always have precedence over the playfield with GR.9 (and charmode with GPRIOR=$4x)

 

Would be interested to know how this effect could be generated (if in fact it is possible)

[pseudografx]

But G2F uses character mode. The extra DMA on the first line makes such changes impossible.

 

And, playing around with Atari800Win+ it seems PMGs ignore their priority bits and always have precedence over the playfield with GR.9 (and charmode with GPRIOR=$4x)

 

Would be interested to know how this effect could be generated (if in fact it is possible)

IMHO a very similar effect could be done with several mid-scanline changes of the background color register.

[Heaven/TQA]

Atari800win seems to show the effect in mode9... check out my intro for abbuc magazine issue 50 years ago...

 

ps. not bad what i have done in my past life... still very stylish... ok. the rotozoomer can be improved a lot and if i would go for a rewrite of that intro i would go for complete HIP mode even for the bar-fx...

intro50.zip

[twh/f2]

Atari800win seems to show the effect in mode9... check out my intro for abbuc magazine issue 50 years ago...

 

ps. not bad what i have done in my past life... still very stylish... ok. the rotozoomer can be improved a lot and if i would go for a rewrite of that intro i would go for complete HIP mode even for the bar-fx...

 

when I understood you right, then this transparency effect on bottom-right corner is realized using missiles, right? also there is no way to use other players for transparency in gr9? Was there a reason for the transparent size (verticaly) and the static positioning? Beside the fact, that it looks very refreshing (not only monochromous), it does not really fit into the screen/demo concept

 

grtx,

\twh

[Heaven/TQA]

and check out P. Dell's (that's his real name... but not a brother of Michael Dell...) his scene handle is JAC! Visdom II demo... it's on the a-side of the Halle Project Demo:

 

you can find the demo here:

 

http://atari.fandal.cz/detail.php?files_id=3726

Edited October 8, 2007 by Heaven/TQA

[Heaven/TQA]

Atari800win seems to show the effect in mode9... check out my intro for abbuc magazine issue 50 years ago...

 

ps. not bad what i have done in my past life... still very stylish... ok. the rotozoomer can be improved a lot and if i would go for a rewrite of that intro i would go for complete HIP mode even for the bar-fx...

 

when I understood you right, then this transparency effect on bottom-right corner is realized using missiles, right? also there is no way to use other players for transparency in gr9? Was there a reason for the transparent size (verticaly) and the static positioning? Beside the fact, that it looks very refreshing (not only monochromous), it does not really fit into the screen/demo concept

 

grtx,

\twh

 

yes. the "block" is made of missles. it was put there only for "style". as it seems you can only make the missles transparent.

[emkay]

basic gr.9 and something like this?

 

---

sta wsync

lda #col1lum0

sta colbak

lda #col2lum0

sta colbak

lda #col3lum0

sta colbak

---

 

?

 

 

That's mainly the correct thing. Only the background colour is changed midline.

 

(Sadly, G2F doesn't support Players and Missiles as possible on the real machine.)

 

Well, doing this inside a demo .... with the missile overlay ....

 

Or , even better, with some GTIA splitting (hires besides lowres colour).... the missiles are used for some FX, the players allow a small game across the coloured background....

 

... or else

 

 

Just to remember. To the right of the screen, the changes are possible with a 2 byte width.

16 luminaces with changing colours in calculateable ranges and missiles for overlay.... What could a clever artist do with it.

[emkay]

But G2F uses character mode. The extra DMA on the first line makes such changes impossible.

 

And, playing around with Atari800Win+ it seems PMGs ignore their priority bits and always have precedence over the playfield with GR.9 (and charmode with GPRIOR=$4x)

 

Would be interested to know how this effect could be generated (if in fact it is possible)

 

G2F supports GED mode which is graphics mode.

[emkay]

@tebe

 

Please make this graphicsmode fully available with all PM features.

[dwhyte]

IMHO a very similar effect could be done with several mid-scanline changes of the background color register.

 

 

How is this mid-scanline change accomplished? I've been trying to do something like that and I can't seem to figure it out. And with a mid-scanline change, am I restricted to just the color registers, or can I change antic modes as well?

[Rybags]

You can change the colour registers but you need to take cycle times and DMA steals into consideration.

 

You can change GTIA mode via GPRIOR from 00 to one of the special GTIA modes. But changing it back to 0 just gives a GR.15 resolution screen with the colour register mapping changed.

 

The method you use for colours would be:

 

1. Setup loop counter for number of scanlines you want - use X or Y, or a zeropage location.

2. STA WSYNC.

3. Decrement loop counter, exit if exhausted. Setup your initial colour value. Optionally load other colour values ready to use in X/Y.

4. Delay - usually just a string of NOPs to waste cycles until the beam is onscreen again. Or, if you have other things to do (like repositioning PMGs), do it. Just make sure the code will use the same number of cycles every time.

5. Store colours, with optional NOPs for delay. This is the super-critical part.

6. Loop back to step 2. You have to ensure you've left sufficient cycles spare as the WSYNC step will create an entire blank scanline if left too late.

[peteym5]

I wonder if there is a bug with Atari800Win with Prior, Player/Missile graphics, and a graphics 9 background. I think someone did mention it is possible to blend the chroma from the player/missiles with the luma from the background. I tried it with the emulator and could not get it to work. What are the PRIOR settings for this?

[gauntman]

Set your PRIOR to 0 (well, with the appropriate GTIA bits as well). I think only the missiles will blend though. I am pretty sure I actually tried this on the real hardware.

[Rybags]

In Gr.9 you need to set the enable 5th Player bit. Then the missiles can act to override the background colour.

 

Problem is, you get the same ORing effect, so they're best left with luminence of 0.

[emkay]

The best results here for having interesting pictures would be to use black for the main screen... putting some colour changes in, adding the Missile overlay and use the players for detail enhancement..... but how to do it in G2F while the features are "blocked"?