The D-sub port on my LCD TV

[thermodan]

1) Can someone please tell me what this means:

The manual for my LCD TV states that:
"This TV's PC input does not support Sync on Green or Composite Sync."

The PC input referred to is a standard D-sub 15-pin female port, with a corresponding stereo audio minijack next to it.

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2) I'm planning on making a custom cable that will connect my official NINTENDO RGB SCART CABLE to the PC port described above (and minijack).

Can anyone see any problem with my plan ?

(I assume the cable I make will only need to be a simple pin-to-pin cable, and won't require any other components ?)

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3) I also just noticed that my LCD TV manual states:

"This TV's PC input does not support interlaced signals."

This sounds like a BIG problem if I want to use a SNES/N64/GCN via this PC port, as I described above.

Is it ?

[NFG]

1. Your VGA port only works with separate, H+V Sync.

2. Your Nintendo's RGB connector only has composite sync.

3. Unless you're using a GameCube via VGA, your TV will not accept any RGB signal from any Nintendo system.

[GZeus]

Note, the SNES doesn't put out an interlaced signal save for 2 Japanese games.
Thing is, it's going to be 30v/15h.
Can your LCD accept that?

[blackevilweredragon]

electrically, 480i and 240p are the same...  (as so i've been yelled at in the past)

[GZeus]

electrically, 480i and 240p are the same...  (as so i've been yelled at in the past)

it doesn't have the second scan.

If it's SD or ED compatible it should work.

[blackevilweredragon]

electrically, 480i and 240p are the same...  (as so i've been yelled at in the past)

it doesn't have the second scan.

it's it's SD/ED compatible it should work.

explain that to Steve Snake, creator of KEGA Fusion..  He got pissed at me because I said that 240p and 480i are different scan rates..  (i still believe this, but what Steve said got me totally confused)

[GZeus]

electrically, 480i and 240p are the same...  (as so i've been yelled at in the past)

it doesn't have the second scan.

it's it's SD/ED compatible it should work.

explain that to Steve Snake, creator of KEGA Fusion..  He got pissed at me because I said that 240p and 480i are different scan rates..  (i still believe this, but what Steve said got me totally confused)

They ARE the same scan rate.
There's just a field that's not displayed.
It effectively runs at 60FPS but you only need to write the game code for 30.
I've spoken with a professional programmer in regards to this point. He loves it, because it's easier.

That's why that vblank period is important. If you have calls made during field 2 in a non interlaced mode you get tearing.
Quote from a pro, not my words.

[blackevilweredragon]

if you program the game code for 30fps, then why do the games run in 60fps?

[NFG]

It's quite possible to write a non-interlaced low-res game that runs at 60Hz.

It's also possible to get a 60Hz TV to display 60 fields per second but only show 30 (or fewer!) frames per second.

For example, if you have a game screen that is static (A title page) that screen is still drawn 60 times per second, even though the image never changes and is technically 1 fps or worse.

So suppose you've got a game that updates 20x per second - each screen would be drawn thrice on a 60Hz TV before being replaced by the next one.

I don't know where I was going with this.  I'll close by saying that TV manufacturer's are cheap bastards.

[blackevilweredragon]

well that bit i knew...

luckily my HDTV is able to recognize 240p sources, but it only does it by detecting vertically doubled pixels...  it then treats it as non-interlaced, and shuts off the deinterlacer, and just upscales to 540p (my TVs picture tube does 540p/1080i only)

[thermodan]

Unless you're using a GameCube via VGA, your TV will not accept any RGB signal from any Nintendo system.

Lawrence,

Why would only a gamecube work via this 15-pin VGA port ?

I will be using a pal-gamecube; but I also have an ntsc-n64 and pal-snes. If there's only a pin for composite sync on the scart cable, then surely none of these consoles will work using the scart cable ?

[NFG]

Why would only a gamecube work via this 15-pin VGA port ?

Because only the GameCube outputs a VGA (31kHz, non-interlaced high-res (ie: progressive) RGB) signal.

PAL GameCube games do not support progressive component or VGA, so if you're using a PAL Cube you'll need a chip and NTSC games.

SCART always uses composite sync.  Always.

[thermodan]

But don't all gamecubes output 'Composite Sync' on pin-16 of the scart cable ?

And if my TV says it doesn't support 'Composite Sync', even an ntsc-gamecube won't ever work on my PC input port, right ?


What is 'Sync' exactly ?

Does:  'progressive'  =  separate V+H sync  ?

And does:  'interlaced'  =  composite sync  ?

[blackevilweredragon]

no...  sync is what pretty much drives the electron gun...

non-interlaced and interlaced can both have H/V and H+V sync lines..  doesn't matter..

[NFG]

You're confusing yourself, thermodan.  Consider the facts:[ol type=\'1\'][li] PAL GameCubes output 15kHz RGB through the multi-AV port, with composite sync, for use with SCART cables.[/li][li] ALL GameCubes can output VGA (31kHz RGB) with H&V Sync through the digital port, with the aid of a modified component cable (though PAL software does not support this).[/li][li] Your TV's 15-pin port is only good for VGA with separated H&V Sync.[/li][/ol]That's what you've got to work with, don't blend the results of one thing (SCART) with another (VGA).  =)

Now, regarding your other questions:

Sync is a signal that pulses at the beginning of every line and the beginning of every screen, so the TV can start drawing at the right time.    When your picture slides around or rolls vertically it's a result of the display not being able to sync with the signal it's receiving.

Progressive and interlaced describe only the method of drawing the image: Draw every horizontal line, or every second one respectively.  That's ALL it connotes.

[thermodan]

Thanks Lawrence, it is clear now :-)

I take it, also, that the Megadrive2/Genesis2 also outputs composite sync (on pin 5) ?

[NFG]

ALL game consoles with RGB output have only composite sync, no exceptions spring to mind.  The GameCube is unique in offering the ability to retrieve H&V Sync.

[blackevilweredragon]

dreamcast..  that does separate H+V sync..  or is that only in VGA mode?  (i was told the dreamcast has 3 RGB modes, C sync RGB, H+V sync RGB, and VGA sync --which is also H+V--)..  i never tested that though..

[NFG]

Ah, yes, the Dreamcast is another exception.  It DOES have H&V outputs when in VGA mode.

[blackevilweredragon]

Ah, yes, the Dreamcast is another exception.  It DOES have H&V outputs when in VGA mode.

yea, that's what i said, but doesn't it have to 15KHz RGB modes too?  it's got two mode pins..  that technically can produce 4 different modes...  (cause, if it was only for VGA, it would have been one mode pin then, which would do two modes)

[NFG]

I don't know the answer to this question.

[blackevilweredragon]

just checked..  if pin 7 is only grounded, it outputs RGB with separate sync..  you'll need to check this cause my LCDs input, when in 15KHz, only takes in comp-sync..  (weird and stupid)

[Endymion]

Perhaps this is the difference in the "two 15KHz RGB modes" that folks were discussing with the Dreamcast in days past. I would not guess that it makes much of a functional difference unless your monitor needed one or the other.

[blackevilweredragon]

that's probably what it is..  i mean, if the DC "can" separate the sync, why not do it for both scanrate modes..  makes sense to me..

[NFG]

I recently had to delete two posts here.  I'd prefer to not have to keep doing this.

I won't have you guys arguing over speculation. If you're not sure of something, be sure to either say as much, or keep it to yourself.  If you ARE sure of something, back it up with some sort of proof before flaming someone.

Getting a bit irritated here, knock it off.