color separately to every pixel in 1024x768

_Alexander

Do I can in the mode 1024*768 to set a color separately to every pixel? (in a demo color it is possible to set only for tiles)
I want to show out any·picture in bitmap.

Peter Jakacki

Do your maths. What your are saying is that 1024*768 = 768K bytes assuming 8-bits/pixel. With 32K of RAM absolute total that leaves a big gap in your display. The Propeller has video capabilities which does not mean that it competes with PC graphics cards which use many megs of RAM and dedicated hardware to achieve something that is nowadays taken for granted but is still no small task, especially for a single-chip.

*Peter*

Mike Green

There's just not enough memory for that large a bitmap. You'd need 24K just for the bitmap plus 6K for the tile table leaves virtually nothing for code or anything else.

_Alexander

OK. If I am to be sending byte after byte total 768K (serial or parallel mode)- its really? example, please.

_Alexander

If i'm connecting its there.

RinksCustoms

This sample chapter may give you some insight for what you are looking for.

As for the case of the TV output the prop generates a series signal throught the 3bit DAC, this is similar for the VGA port, it instead uses (3) 2bit DACs one each for RGB and has the Vsync and Hsync signals attached.

Take a look at what baggers could achieve with the prop and video output in this thread http://forums.parallax.com/showthread.php?p=660936

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Post Edited (RinksCustoms) : 7/24/2007 5:58:11 PM GMT

deSilva

@Alexander: Your idea is very correct and might work except for the fact of the terrible speed needed for VGA:
The dot clock is 25 MHz giving you 40 ns for one pixel. The hardware support allows 16 Pixels to be shifted out before you have to feed the video register again every 640 ns which comes close to 13 instructions, one of it should be a loop jump and one the waitvid, leaving 10 instructions to address the external memory which has to answer within some 100 ns...

Note that you do not only have to fetch 16 bit, but 32 bits plus 32 bits colour map data, which will take 3 cycles through your 20 bit interface...

Though this is possible, it gives you only 4 out of 64 colours within each horizontal 16 bit group I can imagine however that this will not be a very severe handicap when using an appropriate colour pre-processing (to be done by yourself of course..)

When you really want to have different colours to each pixel, you can quadruple the clock speed and output only 4 pixels per WAITVID cyle, which reduces the loop to 160 ns = 3 instructions. This seems imposiible however! When even 640ns seem to tight for your task, you can use two sync-locked COGs, alternately outputting video frames and computing their value.

You should study the drivers called VGA_HIRES...

Post Edited (deSilva) : 7/24/2007 8:31:59 PM GMT

Bob the Builder on a C64

I'd have to say that won't exist for a while unless you use a 1 MB SRAM or more, if you seriously wanted to display something insanely·massive, I'd suggest to get a 2·GB SRAM. Just realize, almost anything can be done with a nice bushel of resistors, alot of RAM, A/V outputs and many propellor chips.

P.S Notice I said MANY, the reason so is that 1 propellor running at 80 MHZ is way too slow for what your getting at. Perhaps 4 or 5 props would do your job best.

But realize this, this isn't exactly what the Propellor is meant for, but, it doesn't mean it can't be done or shouldn't be.

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Post Edited (Bob the Builder on a C64) : 7/25/2007 7:51:14 PM GMT