Wanted: VGA tutorial

ElectricAye

Anybody know a good on-line source that explains how VGA works, how it creates images, how you can use it to play with the colors, text sizes, etc.?

many thanks,
Mark

Franklin

www.google.com/search?q=vga+tutorial&rls=com.microsoft:en-us&ie=UTF-8&oe=UTF-8&startIndex=&startPage=1

▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔
- Stephen

ElectricAye

Okay, so maybe I should have included that I don't know C, nor am I interested in XBOX, etc. etc. etc. etc. etc. etc.etc. etc. etc.etc. etc. etc.etc. etc. etc.etc. etc. etc.etc. etc. etc. and that, yes, I do know how to use Google.

I guess what I was hoping for was more in line with products that Parallax customers are familiar with, as in the Propeller. I guess what I was hoping for was an actual answer and not some cute response.

Mark

▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔
It might be the Information Age but the Eon of Ignorance has yet to end.

Craig Eid

Mark,

What specifically are you looking for? The link that was provided is a good starting point if you want to get a better understanding of how VGA works. The Propeller Object Exchange -·http://obex.parallax.com/objects/search/?q=vga·- has several examples if you are interested in leveraging an existing application.

▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔
························ Craig Eid


··········· Triad Research and Development
Electical Engineering Design and Consulting Services

··················· www.TriadRD.com

ElectricAye

Thanks, Craig. I know next to nothing about how VGA works in general and because there are very few comments in the code provided by the OBEX, I was hoping there was a "how to" manual somewhere on line for the Parallax products. It would be nice to have something that simply provided information like this:

If you want 30 rows by 60 columns, do such and such....
If you want to have blue text on red background, for example, do such and such....
If you want to draw a line from here to there, do x y z....

And so forth and so on.

Right now I'm doing what I almost always end up doing with stuff like this, I'm going through the OBEX and commenting-out code, reverse engineering the code to see what does what. I don't know assembly code, so it's the only way I know to do it. The lack of detailed comments has been my constant complaint about the OBEX code. But it's free, so I guess I should just shut up and sit down.

In the end I'm hoping to have the ability to display about 20 numbers and maybe a graphical display of data as it is generated in real time. I have no need for the cursor capability at this time.

As for the Google results, um, they seemed pretty random to me. Maybe it's obvious to somebody who already knows how VGA works to filter through what is specific to the C language and what is specific to XBOX and what is specific to (fill in the blank) but to my newbie eyes those results appear like a vast impenetrable jungle.

Somewhere, somehow, the computer whizzes on this forum had to learn VGA. I doubt it was transferred to them via genetic memory or neural implants, and so I was hoping one of them could point me to a source that starts at the beginning and leads me to some useable information. Or a suggested book for beginners would be a big help, too.

thanks again,
Mark



Post Edited (ElectricAye) : 4/8/2009 5:00:25 PM GMT

vaclav_sal

This may not be much help, but about 15 yaers ago I had a book about how different monitor format work.

As silly it may sounds , I would Google "CGA, monochrome, VGA".

Cheer up, I hate it too when I get "look it up in Yellow Pages"· answers.

ElectricAye

vaclav,

thanks for the idea. It's not silly at all. In fact, I started looking through ebay for old books on VGA, hoping there's something out there that starts at the beginning. I have no idea what CGA is but I'll take a look.

cheers,
Mark

Bob Lawrence (VE1RLL)

@Mark

Always start with Wiki search:


CGA:
en.wikipedia.org/wiki/Color_Graphics_Adapter


VGA:
en.wikipedia.org/wiki/VGA

▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔
Aka: CosmicBob

Bob Lawrence (VE1RLL)

The graphics drive info below may help you as well.

How to write a graphics driver in 50 lines of code.
:http://forums.parallax.com/showthread.php?p=735672

▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔
Aka: CosmicBob

ElectricAye

Bob,

thanks for the link to the 50 line graphics driver. At first glance it looks like my speed. That's the kind of suggestion I've been looking for.


thanks again,
Mark

Bob Lawrence (VE1RLL)

ElectricAye said...
That's the kind of suggestion I've been looking for.

Ok great! Here's another one for you.

VGA Learning Driver:
http://forums.parallax.com/showthread.php?p=706423

I haven't seen it in a while but stumbled into it again looking for something else.

▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔
Aka: CosmicBob

ElectricAye

Hi Bob,
thanks for that new link. It looks like good stuff. Unfortunately the web link to which Dave Fletcher makes reference appears dead [noparse][[/noparse]edit: I think the article Fletcher references is the same one I found listed below but I'm not sure.]. However, I did find an on-line article written by the same Hwang that provides more pieces to the puzzle. [noparse][[/noparse]edit: This article is VERY good!]

faculty.lasierra.edu/~ehwang/public/mypublications/VGA%20Monitor%20Controller.pdf


It's really too bad there's not a one-stop shopping experience for learning VGA. People in general are most impressed by anything you can get to show up on a TV or TV-like screen. And if a mouse control can be easily added, they are blown away. Such capability is usually associated only with full-blown "professionally" developed equipment. So for me, VGA displays and such help shake off the appearance of my test systems being total kluges (which, I admit, they are). Maybe someday Parallax will put together an educational kit that explains all of these VGA and TV signals from the ground up so that EE-virgins like me can get it up and running within a few hours and be able to talk about it like we really understand it.

thanks again,
Mark



Post Edited (ElectricAye) : 4/11/2009 4:41:29 PM GMT

vaclav_sal

I posted the question on another forum and I think this was the book I was referring to.
·
·
Programmer's Guide to the EGA, VGA, and Super VGA Cards (3rd Edition) (Paperback)
by Richard F. Ferraro (Author)

Cheers Vaclav