GS Mode Selector: Development & Feedback

[reprep]

@SP193:

this should be the link you mentioned:

forums.ps2dev.org :: View topic - SMODE1 question

i recommended ps2videomodes.txt not to you, to the followers who want to help GSM in some way.

I am guessing i might be lucky like the guy in the link and find out some universal values by trial-error method. I can't start doing this now, because GsKit will mess any SYNCV SYNCH value i enter, so i am waiting for GSM integration. I will set the GSM's auto calculations off and experiment on games with different resolutions.

[reprep]

I took RC and LC out of the equaition of our quest to find which register controls pixel-clock ratio, vertical sync, horizontal sync.

VESA-1B and VESA-1C modes have the same RC and LC values but they have different vertical sync. (72 vs 75 hz.)

The new suspects are SYNCH1's HSVS and HSEQ

[Gedankenschild]

[There was a quote by reprep here, but all I got for it was beeing accused of linking... ]


I actually believe that most monitors work perfectly fine with 480p RGB. I own a Gamecube VGA cable. These cables are based on official component[slash*]d-terminal cables (both YPbPr) where the DAC chip (which is inside the cable itself) is soldered to give out RGB instead. The Gamecube, unlike the PS2, doesn't have an actual VGA mode, so this pretty much is HDTV 480p with RGB colors, isn't it? My monitor confirms a resolution of 720x480 with that cable, and they have been used by many people for years and I've never heard anything about only a limited range of screens working with them.

So maybe an alternate (and more compatible) 480p RGB VGA mode might be worth thinking about, when the possibility comes up. And one again thumbs up for all the great stuff going on here recently!



* guess who thinks slashes are only ever used in links...

[No.47]

Some test results for VModeTest v1.01
(hardware: PAL V7, launch method: uLaunchELF v4.42a)

• the 1080p mode still is not recognized by my TV (which should be able to display 1080p via component cable):
  black screen but no BSOD, the PS2 reacts to button presses
• all other vmodes do work now, if tested individually
• when switching between vmodes, the program will freeze eventually:
  e.g. repeated switching between NTSC/PAL and 480p will result in a frozen black image with pink border
• if switching from 1080i to 576p the signal is recognized as 1080i (instead of 576p) and the image is 'blinking'
• if switching from 720p to 576p the signal is recognized as 1080i (instead of 576p) and the image is 'blinking' (similar to above)

[LocalH]

Results for v1.01, SCPH-75001, GS revision 0x1b

NTSC: flawless, "720x484 i 60Hz"
PAL: flawless, "720x576 i 50Hz"
480p: flawless, "720x484 60Hz"
720p: flawless, "1280x720 60Hz"
1080i: flawless, "1920x1080 i 60Hz"
576p: flawless, "720x576 50Hz"
1080p: no signal to my TV, possibly TV issue as PS2 continues to run even after an extended time and I can switch back to any other vmode

I did not notice the issues No.47 did with regards to moving from 1080i or 720p to 576p, although I did get the freezing problem after several switched between no particular vmodes.

[SP193]

Thank you all for the detailed reports.

@No.47: The weird resolution you noticed for the 576P mode might be an error at my end. I wasn't sure of the resolution for 576P mode, so I entered 1440x576 (It's 1280x576, isn't it?).

Or it could be because of some other registers set by the other progressive-scanning modes that I didn't reset.

@All who never got the 1080P mode working: Do your TVs support 1080P @ 30Hz? The problem here is that this 1080P mode isn't running at 60Hz.... so the only thing left is to attempt to double the vertical frequency.

As for the freezing bug.... I cannot comment on why that happens.
But I'm sure that GSM won't cause anything like that.

I actually believe that most monitors work perfectly fine with 480p RGB. I own a Gamecube VGA cable. These cables are based on official component[slash*]d-terminal cables (both YPbPr) where the DAC chip (which is inside the cable itself) is soldered to give out RGB instead. The Gamecube, unlike the PS2, doesn't have an actual VGA mode, so this pretty much is HDTV 480p with RGB colors, isn't it? My monitor confirms a resolution of 720x480 with that cable, and they have been used by many people for years and I've never heard anything about only a limited range of screens working with them.

So maybe an alternate (and more compatible) 480p RGB VGA mode might be worth thinking about, when the possibility comes up. And one again thumbs up for all the great stuff going on here recently!

@reprep too: The RGB mode can be used if you tapped onto the HSYNC and VSYNC connections within the PS2, connected your computer monitor to the PS2, set the colour mode to RGB and set your games to run with progressive scanning. The PS2 will give you a native VGA mode that way.

[E P]

@All who never got the 1080P mode working: Do your TVs support 1080P @ 30Hz? The problem here is that this 1080P mode isn't running at 60Hz.... so the only thing left is to attempt to double the vertical frequency.

1080P works fine here with version 1.01. 1920x1080p @30Hz

The program tends to freeze the most often when switching back to NTSC mode for me.

[reprep]

@SP193: Yup, you are right about RGB issue. So it is better not to hardcode it. I am rather busy so i couldn't test the second version of your app and of course i couldn't experiment on enabling 480p and 720p via registers. I hope, i will be able to do on weekend.

To All: Is there anybody who can make a RGB cable with a SOG disabling circuit for PS2? My TV doesn't have SoG enabled and i want to experiment on GSM VGA modes. Of course all costs and postage will be covered by me. Please contact me if you can help.

[mrcordas]

here are my results with VModeTest
PS2 SCPH 75001 a 40-inch TV with component cable.

all resolutions worked.
and greatly improved, compared with the previous version.
draw your own conclusions with the attachments.

good job.

[SP193]

This is what I've found out so far:

	Definitions:
		SYNCH1:
			HS	- Horizontal Synchronization pulse interval (?)
			HSVS	- Horizontal/Vertical Sync (Period of VS)
			HSEQ	- (Period of VFPE)
			HBP	- Horizontal Back Porch		(lines)
			HFP	- Horizontal Front Porch	(lines)
		SYNCH2:
			HB	- ?
			HF	- ?
			(These two values belong to "HalfH", whatever that is...)
		SYNCHV:
			VS	- Vertical Synchronization pulse interval
			VDP	- Vertical Display Pixels	(Lines)
			VBPE	- ? (Comes before VBP)
			VBP	- Vertical Back Porch		(lines)
			VFPE	- ? (Comes after VFB)
			VFP	- Vertical Front Porch		(lines)

		NTSC 525 lines (480 visible):
			| VFP   | VFPE  | VBP   | VBPE  | VDP   | VS    |
			-------------------------------------------------
 			|  1    | 6     | 26    | 6     |  480  |  6    |

			Vertical lines=1+6+26+6+480+6=525

			| HFP   | HBP   | HS    |
			-------------------------
 			| 64    | 222   | 254   |

			Horizontal lines=64+222+254=540

	Horizontal frequency: (pixel frequency) / (Total number of horizontal lines)
	Vertical frequency: (horizontal frequency) / (Total number of vertical lines)

	References:
		http://infocenter.arm.com/help/topic...1d/DDI0121.pdf
		http://datasheets.maxim-ic.com/en/ds/MAX7456.pdf
		ピクセルクãƒ*ック信å�·ç”Ÿæˆ�装置ã�Šã‚ˆã�³å�ŒæœŸä¿¡å�·ç”Ÿæˆ�装置｜詳細 - astamuse(アスタミューゼ) (Look at diagrams 6 and 7 about HBLANK, VBLANK and CSYNC)
		http://web.mit.edu/6.111/www/f2008/handouts/L12.pdf
		DisplayConfigX

By altering some of these values, the Horizontal and Vertical refresh rates might get changed (Hence explaining why there is no change in the RC and LC values between the VESA 0x1B and 0x1C modes).

The change won't be by a lot though. (It makes sense here, since the gap between the 72Hz and 75Hz VESA modes is not great )

Now we need someone to explain how to encode the RC and LC values, and how they affect the pixel clock....