PDA

View Full Version : Is possible VGA resolution 1024x768 ?



JLS
11-13-2010, 03:49 PM
Hi all

Is possible generate VGA resolution 1024x768 or 640x480 ?

Only for Plot or line function.

Thanks help

kwinn
11-13-2010, 03:57 PM
Depends. The prop can generate video with a resolution as high as 1600 x 1200 but does not have enough memory to store a graphics image at that resolution.

Mike Green
11-13-2010, 04:04 PM
VGA 1024 x 768 is not possible for graphics because there isn't enough memory available for a bitmap. Bill Henning has a dual Prop board with external SRAM and a matching VGA driver that does 1024 x 768 in 4 colors. You might have a look at it (here (http://www.mikronauts.com)). Look at his "Drivers" link.

Rayman
11-13-2010, 04:17 PM
Mike is right. Unless, you want to draw a vertical strip chart:

http://forums.parallax.com/showthread.php?t=106118&highlight=strip+chart[/URL]

[URL]http://forums.parallax.com/showthread.php?t=106710&highlight=Prop+EKG+preview (http://forums.parallax.com/showthread.php?=106118&highlight=strip+chart)

JLS
11-13-2010, 06:32 PM
Thanks info

markaeric
11-15-2010, 01:24 AM
Hi all

Is possible generate VGA resolution 1024x768 or 640x480 ?

Only for Plot or line function.

Thanks help


I've been thinking about this a bit lately. Depending on the length, and the number of lines/plots you need, you may be able to use a sort of bitmap/tile driver hybrid.

I've been thinking about stripping the graphics object down to just the line function, and draw to a temp buffer in the graphics cog - as long as the line size is short enough to fit in said buffer. If you're working with a fixed line length, you can determine the maximum amount of 16x16 tiles that would be necessary to contain the line bitmap, and allocate the appropriate space in the hub. The graphics object would copy only the non-zero tiles, and update the tile map accordingly. As long as you limit maximum number of lines, and their length to not exceed your hub ram bitmap buffer, I don't see why 1024x768 shouldn't be possible.

RossH
11-15-2010, 03:17 AM
Hi all

Is possible generate VGA resolution 1024x768 or 640x480 ?

Only for Plot or line function.

Thanks help

Perfectly possible - I wrote a video driver for the Prop to simulate a vector graphic display, which I used in a a couple of Hydra games - it can do various VGA resolutions up to 1152x864 (2 colors) or 800x600 (4 colors). It's available here (http://forums.parallax.com/showthread.php?t=105213). It has a SPIN interface that is largely code-compatible with the normal Parallax graphics object.

The only limitation is that at the higher resolution you can't draw very many lines on the screen at one time - exactly how many depends on the resolution you choose, and also how much RAM you allocate to the driver.

One day I plan to dust this driver off and use it again - if I ever get enough time :)

Ross.

Invent-O-Doc
11-15-2010, 03:37 AM
Your vector driver sounds very interesting! Will check it out.

markaeric
11-15-2010, 04:48 AM
@Ross

Very cool! How come you never submitted it to the obex?

RossH
11-15-2010, 04:51 AM
Hi markaeric

I guess I never regarded it as "finished". I always wanted to do more with it, but have been unable to find the time.

Maybe I should just package it up "as is" and submit it.

Ross.

JLS
11-15-2010, 08:14 AM
Hi Ross

Many thanks this usefull info.

Today test it :-)