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AiGeneric question - resolved — Parallax Forums

AiGeneric question - resolved

Bill HenningBill Henning Posts: 6,445
edited 2009-12-01 04:14 in Propeller 1
I was trying a new 7" NTSC display, and ran into a weird problem:

- it displays a nice color picture when fed video from a cable box
- it displays B&W with a "herringbone" pattern from the AiGeneric text demo

Same AiGeneric demo works fine on my 3.5" NTSC displays.

Any ideas?

I'll try some other NTSC drivers tomorrow.

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www.mikronauts.com Please use mikronauts _at_ gmail _dot_ com to contact me off-forum, my PM is almost totally full
Morpheusdual Prop SBC w/ 512KB kit $119.95, Mem+2MB memory IO board kit $89.95, both kits $189.95
Propteus and Proteus for Propeller prototyping 6.250MHz custom Crystals run Propellers at 100MHz
Las - Large model assembler for the Propeller Largos - a feature full nano operating system for the Propeller

Post Edited (Bill Henning) : 12/1/2009 4:08:41 AM GMT

Comments

  • potatoheadpotatohead Posts: 10,261
    edited 2009-11-27 04:57
    Interesting... That display might be expecting a full interlaced color signal. AiGeneric does not do this.

    Try the Parallax Driver, and my 80 column text driver. Both of these do interlaced color.

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  • Bill HenningBill Henning Posts: 6,445
    edited 2009-11-27 15:23
    Thanks! I will try...
    potatohead said...
    Interesting... That display might be expecting a full interlaced color signal. AiGeneric does not do this.

    Try the Parallax Driver, and my 80 column text driver. Both of these do interlaced color.
    ▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔
    www.mikronauts.com Please use mikronauts _at_ gmail _dot_ com to contact me off-forum, my PM is almost totally full
    Morpheusdual Prop SBC w/ 512KB kit $119.95, Mem+2MB memory IO board kit $89.95, both kits $189.95
    Propteus and Proteus for Propeller prototyping 6.250MHz custom Crystals run Propellers at 100MHz
    Las - Large model assembler for the Propeller Largos - a feature full nano operating system for the Propeller
  • potatoheadpotatohead Posts: 10,261
    edited 2009-11-28 02:30
    I would also try Eric Ball's templates. They display a simple set of color bars, and are configured for a full interlaced display. If that displays well, then make the edit to the JMP instruction you will find, for a non-vertically interlaced display.

    Do the same for the 80 column text driver, and the Parallax reference driver.

    If both of those display properly in both vertically interlaced and non-interlaced modes, and or the other drivers mentioned display properly, then it's down to the color signal, and or line timing in AiGeneric.

    To factor out line timing and such, go track down Cardboard Guru's simple NTSC demo. That one has fixed color timing also, but slightly different scan line timing from the AiGeneric. AiGeneric was built off of those drivers, and my original 8x8 NTSC drivers. Hippy converted my original ones and there might be some minor league difference that resulted from that.

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  • Phil Pilgrim (PhiPi)Phil Pilgrim (PhiPi) Posts: 23,514
    edited 2009-11-28 03:08
    I've found that LCD displays are much more sensitive to small timing variations than CRTs. What's worked for me to eliminate herringbone patterns is to vary the _xinfreq constant slightly, one way or the other, until the herringbone disappears. This will happen when the stated frequency equals the actual crystal frequency.

    -Phil
  • potatoheadpotatohead Posts: 10,261
    edited 2009-11-28 16:48
    I wonder then what makes some drivers more impacted by this?

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  • Bill HenningBill Henning Posts: 6,445
    edited 2009-12-01 03:38
    I'll try Eric's...

    I tried TV_Text and Graphics_demo today - both showed up in glorious shades of herringboned gray.

    Does anyone have a simple PAL demo? This display is supposedly also PAL compatible.

    potatohead said...
    I would also try Eric Ball's templates. They display a simple set of color bars, and are configured for a full interlaced display. If that displays well, then make the edit to the JMP instruction you will find, for a non-vertically interlaced display.

    Do the same for the 80 column text driver, and the Parallax reference driver.

    If both of those display properly in both vertically interlaced and non-interlaced modes, and or the other drivers mentioned display properly, then it's down to the color signal, and or line timing in AiGeneric.

    To factor out line timing and such, go track down Cardboard Guru's simple NTSC demo. That one has fixed color timing also, but slightly different scan line timing from the AiGeneric. AiGeneric was built off of those drivers, and my original 8x8 NTSC drivers. Hippy converted my original ones and there might be some minor league difference that resulted from that.
    ▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔
    www.mikronauts.com Please use mikronauts _at_ gmail _dot_ com to contact me off-forum, my PM is almost totally full
    Morpheusdual Prop SBC w/ 512KB kit $119.95, Mem+2MB memory IO board kit $89.95, both kits $189.95
    Propteus and Proteus for Propeller prototyping 6.250MHz custom Crystals run Propellers at 100MHz
    Las - Large model assembler for the Propeller Largos - a feature full nano operating system for the Propeller
  • Bill HenningBill Henning Posts: 6,445
    edited 2009-12-01 03:39
    I'd try that if I was getting *ANY* color - but I am not [noparse]:([/noparse]
    Phil Pilgrim (PhiPi) said...
    I've found that LCD displays are much more sensitive to small timing variations than CRTs. What's worked for me to eliminate herringbone patterns is to vary the _xinfreq constant slightly, one way or the other, until the herringbone disappears. This will happen when the stated frequency equals the actual crystal frequency.

    -Phil
    ▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔
    www.mikronauts.com Please use mikronauts _at_ gmail _dot_ com to contact me off-forum, my PM is almost totally full
    Morpheusdual Prop SBC w/ 512KB kit $119.95, Mem+2MB memory IO board kit $89.95, both kits $189.95
    Propteus and Proteus for Propeller prototyping 6.250MHz custom Crystals run Propellers at 100MHz
    Las - Large model assembler for the Propeller Largos - a feature full nano operating system for the Propeller
  • Bill HenningBill Henning Posts: 6,445
    edited 2009-12-01 03:40
    It is really weird, none of the different drivers are generating any color at all.
    potatohead said...
    I wonder then what makes some drivers more impacted by this?
    ▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔
    www.mikronauts.com Please use mikronauts _at_ gmail _dot_ com to contact me off-forum, my PM is almost totally full
    Morpheusdual Prop SBC w/ 512KB kit $119.95, Mem+2MB memory IO board kit $89.95, both kits $189.95
    Propteus and Proteus for Propeller prototyping 6.250MHz custom Crystals run Propellers at 100MHz
    Las - Large model assembler for the Propeller Largos - a feature full nano operating system for the Propeller
  • Bill HenningBill Henning Posts: 6,445
    edited 2009-12-01 04:07
    Always remember the KISS principle.

    I tried the second of the two displays, and what do you know, it works fine!

    This one has a different firmware rev., the OSD is different.

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    www.mikronauts.com Please use mikronauts _at_ gmail _dot_ com to contact me off-forum, my PM is almost totally full
    Morpheusdual Prop SBC w/ 512KB kit $119.95, Mem+2MB memory IO board kit $89.95, both kits $189.95
    Propteus and Proteus for Propeller prototyping 6.250MHz custom Crystals run Propellers at 100MHz
    Las - Large model assembler for the Propeller Largos - a feature full nano operating system for the Propeller
  • potatoheadpotatohead Posts: 10,261
    edited 2009-12-01 04:14
    Probably PAL.

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    Propeller Wiki: Share the coolness!
    Chat in real time with other Propellerheads on IRC #propeller @ freenode.net
    Safety Tip: Life is as good as YOU think it is!
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