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Author Topic: The VideoBlaster Hi Resolution TVout platform  (Read 9197 times)
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I'll see if I can make the colormode to work in tiled mode.

That would enable it to run on a 328.
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I also tried setting up 320x240 50Hz PAL in hope that the TV would display a mixed mode PAL sync and NTSC chroma color.
But it just got confused and displayed BW.

I guess PAL color requiers a 17.72MHz clock to get a 4.43MHz colorburst.

But 320x240 bitmapped mono and a mouse makes a nice desktop.
« Last Edit: December 21, 2013, 06:03:19 am by janost » Logged

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I also have a problem with the top of the screenlines driven to clamp intensity (overdrive and distorsion) on the TV.

I'm guessing it could be caused by the lack of an AC-coupling capacitor on the video output?


* IMAG0168.jpg (646.29 KB, 1500x1054 - viewed 107 times.)
« Last Edit: December 21, 2013, 01:10:03 pm by janost » Logged

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Here is the VideoBlaster code for 320x200 NTSC color bitmapped.
Its all a delicate work of timing so if you change anything there is no support.

I could do it tiled for the 328 but there is no Point in tiled Graphics and color or is there?
It still needs 14.318MHz Clock to show any color.

Happy New Year.

* VideoBlaster.ino (21.67 KB - downloaded 35 times.)
« Last Edit: December 31, 2013, 02:30:27 pm by janost » Logged

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+1
Thanks!  Great effort.

Ray
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+1
Thanks!  Great effort.

Ray

Thanks

If I did anything wrong, please let me know.
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If I did anything wrong, please let me know.

Need to order the 14.318MHz crystal, first... Like 12.5 cents each from Newark... I probably need some stuff anyway  smiley-grin

Ray
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The code I put was actually the Bambino platform BIOS.

So you got the keyboard code as extra.

Never mind, it works anyway.
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This is the best you can do on the mega platform.
Simple and easy.

But you offer processingpower to the video image.

The clockratio is 1:4

With 14MHz you will have just over 3MHz left for the application.
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With 14MHz you will have just over 3MHz left for the application.

Perspective: ... Just over 3 MIPS left...

Ray

Added after reading forward 2 posts:
I Think this is indeed a great effort.  Not being a video-dude (I did work on tube TVs back in high school and did get zapped painfully by a green-screen mono monitor for an Apple II), I am impressed that the little AVR has any bandwidth left.
My 3 MIPs remark is A positive statement, 21% of the uC cycles are still available!  I have not compiled and profiled SRAM and Flash remaining, but with RISC chips my belief is that there is enough left here for some fun!
« Last Edit: December 31, 2013, 08:31:03 pm by mrburnette » Logged

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That is the penelty you pay for doing it single chip.
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I Think I did a great eachievement getting composite color NTSC out of a single AVR chip?
And with that resolution, 320x200?

I cant do better smiley

Anyone? do it better?
« Last Edit: January 01, 2014, 01:03:46 am by janost » Logged

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Note that the chrin() function is mapped for a Scandinavian keyboard (shifted keys 0-9).
I could not get hold of a US/UK keyboard.

It was tough even finding a ps/2 keyboard.

They are all USB nowdays.
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