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Thread: How do I test a PAL video device in USA ?

  1. #1

    Bean's Avatar
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    Default How do I test a PAL video device in USA ?

    I have a video display module made from the SX, and I want to try to adjust the code to support PAL video output.
    How can I get a display that will display PALhere in PA ?

    Bean.


    Post Edited (Bean) : 2/2/2005 5:39:37 PM GMT
    Last edited by ForumTools; 09-30-2010 at 10:53 AM. Reason: Forum Migration

  2. #2

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    The cheapest option you may have is getting a TV tuner card that is PAL compatible. Hop over to www.newegg.com and type "PAL tuner" in the search bar. Have you read Rickard Gunee's article on the SX and television formats? He says that PAL is very difficult to get right without a chip speciallydesigned for PAL video, so good luck!

    Paul
    Last edited by ForumTools; 09-30-2010 at 10:53 AM. Reason: Forum Migration

  3. #3

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    Thanks Paul,
    I'm only doing black and white so it should be do-able.
    I also found out that my camcorder has a PAL input option, so I'll try that first.

    Bean.
    Last edited by ForumTools; 09-30-2010 at 10:53 AM. Reason: Forum Migration

  4. #4

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    In that case (mono only), you'll get usable results from any vaguely competent NTSC TV - the sync schemes are similar enough that most chipsets will lock on fine. If you have to generate PAL-60 because your TV's really fussy, then that's not too hard.
    If you're trying to generate proper (saleable) PAL, then ebay yourself a broadcast monitor, and play in comfort.
    (We've used SX28s here to insert, errr, stuff, into video, using an R/2R DAC on teh pins. It works well, but does require much care)

    Steve
    Last edited by ForumTools; 09-30-2010 at 10:53 AM. Reason: Forum Migration

  5. #5

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    Is PAL-60 60Hz ?

    I need to generate PAL for use overseas, I assume that is 50Hz.

    Now I wonder if my camcorder is 60Hz or 50Hz ???

    Bean.
    Last edited by ForumTools; 09-30-2010 at 10:53 AM. Reason: Forum Migration

  6. #6

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    Yeah - I doubt it's any kind of a standard, but it's pretty commonplace. If you can't be bothered to do the conversion (which is lossy, and hard), lots of pieces of kit just let you switch to another colour encoding scheme, keeping the line & frame rates unchanged. Cheap-tat DVD players, for instance, often resort to this when playing out-of-region discs.
    Whether you want to do the whole job properly depends very much on what you're trying to do. If you're doing this for a customer, it's worth finding out what they want / need / are prepared to pay for. If you're just playing around, then play! You might be surprised by what TVs will lock to.
    (I've been designing set-top boxes for a while - hence the rather jaded viewpoint :)

    Steve
    Last edited by ForumTools; 09-30-2010 at 10:53 AM. Reason: Forum Migration

  7. #7

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    This is my own design of a video display terminal using the SX. It is strictly black and white.

    It works great on NTSC, but I would like to support PAL output for potential customers across the pond.

    I double checked my camcorder and it does NOT display PAL. So I think I'll go with the video capture card route.

    Bean.
    Last edited by ForumTools; 09-30-2010 at 10:53 AM. Reason: Forum Migration

  8. #8

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    One option you could look at is the small 5 or 7 inch lcd displays that are used for portable dvd players. Some of these are PAL/NTSC switchable, you should be able to find some on ebay or the likes. Not real cheap, but should work for what you want.
    kelvin
    Last edited by ForumTools; 09-30-2010 at 10:53 AM. Reason: Forum Migration

  9. #9

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    I purchased a hauppauge WinTV card, installed it. They give several different PAL options. PAL-M, PAL-N, PAL-BGIxx. I checked the input with my digital camera (that has PAL output). And it seems the PAL-BGIxx was what I wanted. Anyway the card works well and I was able to get a good picture by changing some of the timing.

    Thanks for all the ideas...

    Bean.
    Last edited by ForumTools; 09-30-2010 at 10:53 AM. Reason: Forum Migration

  10. #10

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    I can't resist to place a post here:

    Do you know what these fancy abbreviations NTSC, PAL, and SECAM really mean?

    NTSC = Never Twice the Same Color
    PAL = Pay for Additional Luxury
    SECAM = Systeme Elegante Contre l'AMerique

    ▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔
    Greetings from Germany,

    GŁnther
    Last edited by ForumTools; 09-30-2010 at 10:53 AM. Reason: Forum Migration

  11. #11

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    I've always heard the eurocentric PAL="Perfect At Last"
    Last edited by ForumTools; 09-30-2010 at 10:53 AM. Reason: Forum Migration

  12. #12

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    Paul,

    good point - this comes closer to the French SECAM stuff

    ▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔
    Greetings from Germany,

    GŁnther
    Last edited by ForumTools; 09-30-2010 at 10:53 AM. Reason: Forum Migration

  13. #13

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    Bean -

    You may want to check in to what parts of the world support what PAL standard. I know there are some oddballs. For example, PAL in Brazil uses PAL timing but NTSC resolution.

    I used an add in tuner card to test my video device (http://www.speechchips.com/shop/item.asp?itemid=29) and I bought a small BW PAL monitor to test with. Oddly enough, the monitor is a pretty forgiving device.

    Ken
    www.speechchips.com
    Last edited by ForumTools; 09-30-2010 at 10:53 AM. Reason: Forum Migration

  14. #14

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    Ken,
    I actually saw your video device while browsing for similar products. Looks pretty cool.
    I wish the SX had more RAM so I could use a higher graphic resolution.
    Maybe some day I'll port it to the SX48 or SX52. The extra code space would help too.

    I too am amazed at how forgiving the monitor is (both NTSC and PAL). It seems like as long as the sync pulses are regular enough, the monitor can figure it out. I actually got alot of good info from web site that describe the video output from the old ZX81 computer. Just one very long VSYNC pulse, seems to work fine.

    Bean.

    ▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔
    Check out the "SX-Video Display Module"

    www.TerryHittConsulting.com


    Post Edited (Bean) : 2/17/2005 12:19:14 PM GMT
    Last edited by ForumTools; 09-30-2010 at 10:53 AM. Reason: Forum Migration

  15. #15

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    Bean,

    Yes, extra ram helps. I'm using 800 bytes for pixel adressable screen buffer to get a monochrome resolution of 64x100.

    My next project, the SV2000, is 128x128 but that is character based.

    So have you started on a color version?
    Last edited by ForumTools; 09-30-2010 at 10:53 AM. Reason: Forum Migration

  16. #16

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    Bean said...
    Is PAL-60 60Hz ?

    I need to generate PAL for use overseas, I assume that is 50Hz.

    Now I wonder if my camcorder is 60Hz or 50Hz ???

    Bean.
    Bean,

    IMO, PAL actually is a definition of one method to encode/decode color information on a TV signal. As your device just outputs b/w, you don't need to bother about the color system. On the other hand, there is another standard, CCIT which defines the frame/line rates. Most commonly used in Europe is a frame rate of 50 Hz, and a line rate of 15,625 Hz, i.e. 50 half-frames/second, 625 lines, odd lines first, even lines next.

    ▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔
    Greetings from Germany,

    GŁnther
    Last edited by ForumTools; 09-30-2010 at 10:53 AM. Reason: Forum Migration

  17. #17

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    Bean, if you register at ITU they allow you to download 3 documents for free. ITU-R BT.470-6 "Conventional Television Systems" (the 98 dated one), provides information on the three main systems and thier variants. Its not the easiest thing to read, but it does contain useful information I haven't seen in other online sources (and its free) (Like a table of what standard and variant every country uses, as well as side by side table characteristics for all the variants (for example in table 1 it states the frame rate of NTSC (designated M) is 59.94 and all other standards are 50 frames per second).

    Ignore the fact that the standard states its superceded, the more recent document is more of an errata and doesn't provide any "meat".
    Last edited by ForumTools; 09-30-2010 at 10:53 AM. Reason: Forum Migration

  18. #18

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    Guenther,
    Yeah the PAL video capture card will display the NTSC output, but it gets squashed to the top. When you use the PAL output option I just use more vertical lines.
    Bean.

    ▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔
    Check out the "SX-Video Display Module"

    www.TerryHittConsulting.com
    Last edited by ForumTools; 09-30-2010 at 10:53 AM. Reason: Forum Migration

  19. #19

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    Hey Bean did you do the commercial vsync or do the inverted hsync method for vsyncing?
    Last edited by ForumTools; 09-30-2010 at 10:53 AM. Reason: Forum Migration

  20. #20

    Bean's Avatar
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    Not sure what you mean by "commercial vsync" ?
    What I do for VSYNC is just a single very long sync pulse (ala Sinclair ZX81 video routine).
    I need the cycles for the main program to execute.

    Bean.

    ▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔
    Check out the "SX-Video Display Module"

    www.sxvm.com
    Last edited by ForumTools; 09-30-2010 at 10:53 AM. Reason: Forum Migration

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