HomeForumsWhat's newResources 
 
 
No sprites with 704px?
RockinB - May 3, 2006
  RockinB May 3, 2006
I've been playing around with display modes and figured out that the SGL sprite display does not work, when the VDP1 horizontal resolution is set to 704.

It's not due to the clock change involved, because 352 works. It's also not due to hires, because 640 works.

Anyone got a clue? :huh The VDP1 manual lists a display mode with 704px width. I think it should work, but it doesn't. So when using 704px scrolls, I can only use 352px sprites which is a workaround, but below possibilities.

Another question: does VDP1 support 512px vres? The docs say no, but the SGL at least displays sprites with this setting, though I don't know if it falls back to a different res.

BTW: I managed display of 704x512 on a PAL TV, damn it looks good! :smash

 RockinB May 4, 2006
Problem found:

With different screen resolution, the view frustrum changes. I always used a Z-Value of about 169.0, which has proved to make sprites visible. Now with 704px the Z-Value has to be higher to be inside the view volume. That's all.

 Zaksund May 8, 2006

  
	
	

		
		

			Originally posted by Rockin'-B@Wed, 2006-05-03 @ 04:22 AM



BTW: I managed display of 704x512 on a PAL TV, damn it looks good! :smash




[post=146044]Quoted post[/post]


I'm dunno about anyone else, but I'm totally jealous! That must look incredible!

 Omni May 8, 2006
Wouldn't you need a special component-like cable for the Saturn to do EDTV resolution like that? Or do you have to create your own?

 ExCyber May 8, 2006
I think that resolution should be fine with the encoder if it's interlaced...

 cgfm2 May 8, 2006

  
	
	

		
		

			Originally posted by Omni@Mon, 2006-05-08 @ 12:26 PM



Wouldn't you need a special component-like cable for the Saturn to do EDTV resolution like that? Or do you have to create your own?




[post=146134]Quoted post[/post]


The non-EDTV modes are 320x224 to 704x512 interlaced, and those will display fine over a S-Video or composite video cable. They are all 15 KHz and fit within the regular PAL/NTSC video timings.

The EDTV modes (320x480 to 704x480) are non-interlaced and run at 31 KHz, so you need a multisync monitor (and therefore an RGB cable) to view them.

I know nowadays some video encoders are made to handle non-standard inputs, so perhaps the one in the Saturn could keep up - but then again I've never heard of any monitors designed to handle S-Video or composite video at sync rates above 15 KHz. Maybe such a thing exists?

 Omni May 8, 2006
Notes for the ignorant self:

1. This would require construction of an RGB-type cable for the Saturn? (certainly never heard of one in stores)

2. What exactly is the 'encoder' you speak of? Something entirely different?

EDIT: More searching on web done.

Okay. So...assuming that I locate a Japanese RGB cable. If I run a Saturn through the RGB cable to a RGB/YUV converter box that could output component video, and then to an HDTV, could I actually enable 480p (which I assume is "non-interlaced") in programming?

It wouldn't work for commercial games, of course, but it would be kinda cool to experiment with it...

 slinga May 11, 2006
Looks like the Saturn can already support 480p (640x480) if I'm reading this right. Look on page 12 of the VDP2 User's Guide. The second to last TV mode is 640x480 non-interlaced.

Edit: The saturn has atleast two RGB cables that I know of. One to support Japanese/US TVs and one to support European.

 Omni May 11, 2006
Yes, I mean, my question was how exactly to get it hooked up to an HDTV to do so, considering there's no "Saturn component cable" and I'm not exactly HDTV-savvy.

 ExCyber May 11, 2006

  
	
	

		
		

			Originally posted by Omni



What exactly is the 'encoder' you speak of? Something entirely different?

The encoder is the component that translates the RGB signal into an NTSC/PAL-encoded signal (i.e. S-Video/Composite). Using an RGB cable bypasses this process which means your signal is no longer limited by the encoding process (though it may be bandwidth-limited by an amplifier; not sure exactly what the RGB output goes through on Saturn).

 cgfm2 May 11, 2006

  
	
	

		
		

			Originally posted by Omni@Mon, 2006-05-08 @ 11:20 PM



Notes for the ignorant self:



1. This would require construction of an RGB-type cable for the Saturn? (certainly never heard of one in stores)


Yes. The monitor I use has a DB9 connector for RGB video, so I installed a matching connector on the Saturn and soldered wires from it to the various test points on the PCB where the video signals (red, green, blue, c-sync) were present. Works like a charm. The Saturn video is a bit dark compared to other RGB sources, but apart from a brightness control tweak everything else (gamma, etc.) is perfect.

You can get RGB video out of it's A/V connector on the back, but I didn't want to try and locate a PAL SCART or Japanese 21-pin (D-type or whatever) connector and hack it to death to hook up to my monitor.


  
	
	

		
		

			2. What exactly is the 'encoder' you speak of? Something entirely different?


ExCyber pretty much covered this. I don't know what the Saturn uses (a Sony CXA1145?) but it would be interesting to find out. Maybe I should have said 'RGB to composite/S-Video converter' for clarity.


  
	
	

		
		

			Okay. So...assuming that I locate a Japanese RGB cable. If I run a Saturn through the RGB cable to a RGB/YUV converter box that could output component video, and then to an HDTV, could I actually enable 480p (which I assume is "non-interlaced") in programming?


That sounds correct. I don't know what kind of horizontal scan rates an HDTV will sync to, but if it can do ~31KHz you are probably OK. The 320x480 and 640x480 modes are 31 KHz exactly, I think the 352x480 and 704x480 modes are slightly higher.

And it is fun to use in your own programs. There are strange some limitations to how the backgrounds can be used, but having basically VGA-equivalent video from the Saturn is nice.

 ExCyber May 11, 2006

  
	
	

		
		

			Originally posted by "cgfm2"



I don't know what the Saturn uses (a Sony CXA1145?) but it would be interesting to find out.

If memory serves, that's what I saw on the two Saturn mainboards I've looked at. Unfortunately I don't have them with me at the moment.