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GT Turbo

a 688*576 picture on Jaguar !

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Thanks for the comments, everyone :)

Don't forget to try out the 1376x576 version also (different picture) ;)

Edited by Zerosquare

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My screen wont stop rolling.

 

 

Yes, because it's 50 Hz only. In 60 Hz mode, you have to do a lot of modifications, i have asked Zerosquare for that, but i think he can explain the why ;) by itself

 

 

 

GT Turbo (JagWare) ;)

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Hello!

 

Zerosquare strike back with a 1376*576 picture on a Jag !!

 

http://www.jagware.org/index.php?showtopic=230

 

Unfortunately a normal CathodeRayTube can only display about 768 pixels per scanline(*),

but great to hear that you are exploring this topic further ;-)

 

Regards

Matthias

 

(*) = I know that there are no real "pixels" on a scanline of a CRT, it's the calculated value for the used video-signal.

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Hello!

 

Zerosquare strike back with a 1376*576 picture on a Jag !!

 

http://www.jagware.org/index.php?showtopic=230

 

Unfortunately a normal CathodeRayTube can only display about 768 pixels per scanline(*),

but great to hear that you are exploring this topic further ;-)

 

Regards

Matthias

 

(*) = I know that there are no real "pixels" on a scanline of a CRT, it's the calculated value for the used video-signal.

 

I use my MADCATZ LDC (it's NTSC) I found it can handle PAL resoution but the games or progroms needs to be in "In a 60 Hz mode"

Edited by walter_J64bit

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Hi GT,

Yes it's possible, when Zerosquare do nothing, he do some nice code, enjoy this one :
Great to see you chaps still experimenting.

First published interlace code is in Tempest 2000, but this looks nicer!

Cheers, keep up the good work!

Regards,

JustClaws.

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Again, thanks for the positive feedback. I'm still polishing the code, and planning to add a 60 Hz version ; details on how to setup the modes will be released publicly.

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My question is: (sorry, I didn't read ALL the discussion -both there and at JS2-)

May this image be used as a backgroung in a true game?

Or the Jag is too much busy in keeping it onscreen?

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There are several points to consider :

 

1) Processors usage is not a problem since the Object Processor is the one doing the hard work.

2) Interlacing does not require additional resources per se (although there are twice as many lines to display, they are refreshed half as often).

3) Higher horizontal resolutions use more bandwidth on the internal bus ; it can slow other things down.

4) Large pictures need a lot of ROM to store them, and a lot of RAM to display then (it's less of a problem with SCPCD's JagCF card).

 

I've not done any benchmarking yet, but my feeling is that 1376x576 would be only interesting for still pictures (there are limitations on sprites in this mode anyways), and that 688x576 would still be interesting for general use (but don't quote me on that :) )

Edited by Zerosquare

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First published interlace code is in Tempest 2000, but this looks nicer!

 

You know.. I honestly dont know if that is truly interlace...Or if it is something even related to interlace... I have no idea what it does except "shake" the text.... (interlace "flickers" in Y direction.. but tempest "shakes" the text... in X..and probably Y aswell..)

 

So as far as i knew I was the first one that did true interlace in december 04... (but thought to have it as a "ess" up my sleve for a bigger demo release... but Zerosquare beat me to it ;) ... which is ok... Im just glad some hackers are emerging in the scene...

 

This is offcourse if not someone else did like I did and kept it a secret ..perhapps it was done eons ago but never got to see the light of day... (perhapps it was tested by atari but banned & forbidden to be use by licensed games... we never know).

 

But it opens the path for the first, retro, SlideShow demo on the jaguar =) ...jeyyy =)

 

regards

/Sym

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So as far as i knew I was the first one that did true interlace in december 04... (but thought to have it as a "ess" up my sleve for a bigger demo release... but Zerosquare beat me to it ;) ... which is ok... Im just glad some hackers are emerging in the scene...

 

This is offcourse if not someone else did like I did and kept it a secret ..perhapps it was done eons ago but never got to see the light of day... (perhapps it was tested by atari but banned & forbidden to be use by licensed games... we never know).

 

Doesn't count unless you release it! Keeping it secret means you didn't do it.

Cheers

A

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perhapps it was tested by atari but banned & forbidden to be use by licensed games... we never know

That's likely, considering the fact that you need to modify the VP register for interlacing to work, and this quote from the Jag's Release Notes (see the attached picture).

post-8748-1147007536_thumb.jpg

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Doesn't count unless you release it! Keeping it secret means you didn't do it.

 

What doesnt count? ...the fact that Tempest isnt true interlace, or the fact that I did true interlace in Dec-04, or the fact that ZeroSquare released the first true interlace for the jaguar? ...

Lets stick to facts not fiction please, just because someone didnt experience WW2 doesnt mean it didnt happen..

 

 

Zerosquare:

Yes that is what i meant... atari never wanted their coders to poke around with these registers.. and you need to poke alot to get interlace.. Hence my oppinion that its possible that this is a "first time experience" for the jaguar..

 

Or perhapps its unstable in a way we havent experienced yet... ?

I would urge ALL with a BJL to test this demo on all jaguar series.. so we get a verification that the method works stable on all jaguars.

 

regards

/Sym

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2) Interlacing does not require additional resources per se (although there are twice as many lines to display, they are refreshed half as often).

 

If one were writing a Doom-style game that was capable of updating the screen at 60fps, it should be able to handle interlacing at full-speed. If the game was only capable of running at a lower frame rate, using an interlaced display would make things worse.

 

One thing I've wondered about with NTSC is whether it would be possible to jinx the vertical timing to get a 3:1 interlacing pattern. The serration pulses would be non-standard, but I would think that if the signal was generated properly it should work on most television sets.

 

Actually, one thing I would have liked to have seen emerge as a standard for use with DVDs would have been a video format with 72 fields/second 24 frames/second using NTSC-standard horizontal scanning. That would have allowed enhanced vertical resolution (compared with NTSC), proper movie frame rate, and minimal additional electronic complexity. Never happened, of course.

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For the curious, I've released some info about video on the Jag (not everything yet... see the link for the explanation :P) here. We've also discovered that Tempest 2000 "interlace"... doesn't.

Edited by Zerosquare

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Could the Jaguar do 720x480 pixels in widescreen like an NTSC dvd player would?
Yes. In fact, the Jaguar can output up to approx. 1400 pixels per horizontal line in 60 Hz mode -- better than a DVD player.

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