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Main => Monitor/Video Forum => Topic started by: BLACK KNIGHT on December 09, 2004, 06:33:13 pm

Title: You can't go above 640x480 on a TV??
Post by: BLACK KNIGHT on December 09, 2004, 06:33:13 pm
Just making sure...I'm pretty sure you can't.  Also what color depth is best to use for Windows.
Title: Re: You can't go above 640x480 on a TV??
Post by: eyal8r on December 09, 2004, 08:19:40 pm
Well, Im using XP Home, Mame32, and a new Radeon 7000 card- the smallest resolution is 800x600- runs MAME fine. It doesn't even give me the option to go lower- weird, huh?
Anyone else?
Title: Re: You can't go above 640x480 on a TV??
Post by: Tritoch84 on December 09, 2004, 08:29:37 pm
Uh, whoever told you that you can't go above 640X480 on a TV is wrong. I would ignore this man/womans advice.
Title: Re: You can't go above 640x480 on a TV??
Post by: SOAPboy on December 09, 2004, 08:36:25 pm
Quote from: Tritoch84 on December 09, 2004, 08:29:37 pm
Uh, whoever told you that you can't go above 640X480 on a TV is wrong. I would ignore this man/womans advice.

yup.. my TV in my living room does 1024x768 just fine.. same with my mame TV..

Title: Re: You can't go above 640x480 on a TV??
Post by: wboy on December 10, 2004, 05:55:54 am
The best matched resolution for a NTSC signal is 720x480.  Supported by many ATI cards with TV out  (last I looked any way).

Anything above is effectively actively resized to the 720x480.

Interesting read re: resolutions and DVDs at - kinda related:
http://www.michaeldvd.com.au/Articles/PALvsNTSC/PALvsNTSC.asp
Title: Re: You can't go above 640x480 on a TV??
Post by: Silver on December 10, 2004, 10:21:35 am
In reality its not quite that straightforward.....

A 'normal' TV signal - NTSC or PAL is *ALWAYS* 575 or 625 horizontal lines. I am not talking HDTV or digital signals etc...

I presume everyone above is using TV-out from a gfx card.  When you change the resolution around - 640x480 or 1280x1024 or whatever, the graphics card and drivers convert the picture to something that has 575ish lines and then encode it to PAL/NTSC and send it out. So you are not really getting a higher resolution on the TV, its just making everything smaller.

This is why text in Windows is MUCH easier to read on a TV when you are in 640x480 compared to 1280x1024.

However, most modern graphics cards - especially ATI - do an extremely good job of outputting good quality TV pictures, so just go with what looks good.

You will probably only run into restrictions of resolution when you are outputting to BOTH a TV and a PC Monitor at the same time - the max resolution will be lower here.

Title: Re: You can't go above 640x480 on a TV??
Post by: ericball on December 10, 2004, 12:14:44 pm
Note: 525/625 (NTSC/PAL) is the number of total lines (interlaced) and doesn't take into account vertical blanking.  480/576 is what a DVD uses and is about the maximum you can expect (and you will probably still lose some lines to overscan). 

Horizontal resolution is a function of the pixel clock & blanking ratio.  So a DVD (720x480) uses a 13.5MHz dot clock, which gives a total line of 858 pixels.  And that 720 is optimistic and subject to overscan, 704 is more typical for onscreen.  Square pixel NTSC (640x480) has 780 pixels per line or a 12.27MHz dot clock.  Composite will top out at 320/455x480 due to aliasing with colorburst frequency (3.57MHz) (and has lower color resolution).  S-Video limits the color resolution to 3.57MHz, but opens up the pixel clock.