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View Full Version : TV (composite video) - Anyone use P15 (aural subcarrier in broadcast mode)?



Cluso99
07-17-2009, 03:16 PM
In a design I require the use of the pin for a different purpose and was wondering if anyone is using this function with composite video?

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· Emulators: Micros eg Altair, and Terminals eg VT100 (Index (http://forums.parallax.com/showthread.php?p=778427)) ZiCog (Z80), MoCog (6809)
· Search the Propeller forums (via Google) (http://search.parallax.com/search?site=parallax&client=parallax&output=xml_no_dtd&proxystylesheet=parallax&proxycustom=<HOME/>&ie=&oe=&lr=)
My cruising website is: ·www.bluemagic.biz (http://www.bluemagic.biz)·· MultiBladeProp is: www.bluemagic.biz/cluso.htm (http://www.bluemagic.biz/cluso.htm)

BradC
07-17-2009, 03:45 PM
Cluso99 said...
In a design I require the use of the pin for a different purpose and was wondering if anyone is using this function with composite video?


Absolutely. Every board I have that has a TV output is using the 4th pin for some other function. As long as it's not an output in the TV cog there is no interference anywhere else.

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Release the hounds!

ericball
07-18-2009, 12:49 AM
This question has been asked previously: http://forums.parallax.com/showthread.php?p=810742

P15 is used for:
Aural subcarrier in broadcast mode. Chroma for S-Video output. My NTSC240H sprite driver uses all 4 pins to get brighter colors. However, the palette could be customized to only use 3 pins (or use 8 pins for 4+4 SVideo).

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Composite NTSC sprite driver: Forum (http://forums.parallax.com/showthread.php?p=800114)
NTSC & PAL driver templates: ObEx (http://obex.parallax.com/objects/483/) Forum (http://forums.parallax.com/showthread.php?p=803904)
OnePinTVText driver: ObEx (http://obex.parallax.com/objects/480/) Forum (http://forums.parallax.com/showthread.php?p=822453)

Cluso99
07-18-2009, 05:45 AM
ericball: Yes I had missed that thread. But, not many answered the question. The board I am doing is for general use plus some extras, and I want to use this pin. So this is why I am wanting to know how many use the pin for TV broadcast (or like you). As there is VGA, it could be used rewired to produce TV if necessary.

▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔
Links to other interesting threads:

· Home of the MultiBladeProps: TriBladeProp (http://forums.parallax.com/showthread.php?p=786418), RamBlade (http://forums.parallax.com/showthread.php?p=810753), TwinBlade (http://forums.parallax.com/showthread.php?p=806697),·SixBlade (http://forums.parallax.com/showthread.php?p=780033), website (http://bluemagic.biz/cluso.htm)
· Single Board Computer:·3 Propeller ICs·and a·TriBladeProp board (ZiCog Z80 Emulator) (http://forums.parallax.com/showthread.php?p=790917)
· Prop Tools under Development or Completed (Index) (http://forums.parallax.com/showthread.php?p=753439)
· Emulators: Micros eg Altair, and Terminals eg VT100 (Index (http://forums.parallax.com/showthread.php?p=778427)) ZiCog (Z80), MoCog (6809)
· Search the Propeller forums (via Google) (http://search.parallax.com/search?site=parallax&client=parallax&output=xml_no_dtd&proxystylesheet=parallax&proxycustom=<HOME/>&ie=&oe=&lr=)
My cruising website is: ·www.bluemagic.biz (http://www.bluemagic.biz)·· MultiBladeProp is: www.bluemagic.biz/cluso.htm (http://www.bluemagic.biz/cluso.htm)

Phil Pilgrim (PhiPi)
07-18-2009, 06:22 AM
I've used it before and do provide the necessary DAC resistor for it on the boards I design. But, as of June here in the 'States, analog broadcast TV is gone, so the pin's long-term utility for an audio subcarrier is virtually nil, as far as I can tell.

-Phil

hover1
07-18-2009, 06:54 AM
Ray,

I understood the original question this morning. Just getting a chance to answer.

I the 10-12 projects I have done so far NONE have had to use this pin. I have often thought of cutting the resistor off of the demo board to use it, but so far I have not had to. It would be a shame to hack a nice Parallax board. My boards, not a second thought http://forums.parallax.com/images/smilies/tongue.gif

Jim


Cluso99 said...
ericball: Yes I had missed that thread. But, not many answered the question. The board I am doing is for general use plus some extras, and I want to use this pin. So this is why I am wanting to know how many use the pin for TV broadcast (or like you). As there is VGA, it could be used rewired to produce TV if necessary.