Amiga.org
Amiga computer related discussion => Amiga Desktop Audio and Video => Topic started by: trekiej on June 16, 2007, 06:33:48 AM
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I have been looking at how the NTSC signal is produced.
( composite signal )
I have gone to www.ntsc-tv.com and downloaded some of the pics.
When it comes to explaining the Vertical Sync Pulses it seems to just end.( they do not go into much more detail)
Maybe I just do not get it.
The Vert. Pulses seem to go to blacker than black and then back up to black. They do not go into detail on how wide the vert. Pulse needs to be. Okay, they say 63.5 uSec for each line. It show approximately 19 to 20 lines get blanked.
VGA will be much better, I hope. Since it has the Sync Pulses on different lines.
Info. is much appreciated and needed.
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I remember that people used to do wild programming of the vertical blank interrupt.. I would google around that..
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Thanks. I do not know for sure what you are saying and how it refers to the ntsc and pal signals. I will look.
Later.
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The source of all of this comes from the "Build Your Own Game Console" book sold by www.xgamestation.com
It shows how to use an SX28 chip to make NTSC/PAL signals.
It is a pain to learn the Vertical Blanking section of it.
How does the H/V sync pulses get separated and what are the differences. Pulse width?
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Maybe try this:
Http://www.videointerchange.com
There is all sorts of crap and detailed info here
Wol.
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Thanks to all.
I basically got it figured out.
The Vertical Sync Pulses get sent through a Low Pass Filter. Their pulse widths are much wider than the H/Sync pulses. H/Sync can not go through.
All is left is to find out how to distribute the pulses.