Commodore 128 Alive!

Commodore 128 => Herdware => Topic started by: redrumloa on March 23, 2008, 02:42 AM

Title: Mangelore's RGBi/CGA/VGA modification
Post by: redrumloa on March 23, 2008, 02:42 AM
First off, thanks to Fotios for figuring out this mod in the first place! As I'm sure you've seen, a few colors are off.

Mainly:
Orange looks dark purple
Dark Grey looks light blue

Has anyone figured out how to fix this? Thanks in advance!
Title: Re: Mangelore's RGBi/CGA/VGA modification
Post by: redrumloa on March 23, 2008, 04:00 AM
After some playing, I'm thinking of replacing the built in potentiometers. The ones that come on this board only go to 1K Ohm and after tinkering I think increasing resistance may bring colors in more.
Title: Re: Mangelore's RGBi/CGA/VGA modification
Post by: redrumloa on March 23, 2008, 04:44 AM
Umm.. Maybe I took stupid pills this morning. I just hooked up my 1902 and the colors look like they are close to the same. I'm going to take a pic of the 1902 image and compare to the adapter output.
Title: Re: Mangelore's RGBi/CGA/VGA modification
Post by: redrumloa on March 23, 2008, 04:50 AM
(http://i28.tinypic.com/1zxo9dd.jpg)


color palette on a 1902.
Title: Re: Mangelore's RGBi/CGA/VGA modification
Post by: redrumloa on March 23, 2008, 05:15 AM
Ok here is the VGA output, after tinkering with the pots a bit.

(http://i27.tinypic.com/2ih9mvl.jpg)


Closer than I was thinking, mainly only color 11 is off. Quite doable as-is.
Title: Re: Mangelore's RGBi/CGA/VGA modification
Post by: Andrew Wiskow on March 23, 2008, 05:42 AM
Quote from: redrumloa on March 23, 2008, 02:42 AM
First off, thanks to Fotios for figuring out this mod in the first place! As I'm sure you've seen, a few colors are off.

Mainly:
Orange looks dark purple
Dark Grey looks light blue

Has anyone figured out how to fix this? Thanks in advance!

It's not a matter of fixing anything...  The 16 colors in 80-column mode are different than the 16 colors in 40-column mode.

These are the most noticable differences:

40-column "purple" looks like "hot pink" in 80-columns.
40-column "orange" looks like "dark purple" in 80-columns.
40-column "brown" looks like "puke tan" in 80-columns.
40-column "pink" looks like "bright red" in 80-columns.
40-column "dark gray" looks like "dark cyan" in 80-columns.
40-column "medium gray" looks like "dark gray" in 80-columns.

These color names are, of course, my own opinion...  I don't think you'll find a crayon that's labeled "puke tan".  ;)

-Andrew
Title: Re: Mangelore's RGBi/CGA/VGA modification
Post by: Golan Klinger on March 24, 2008, 02:34 PM
Quote from: Andrew Wiskow on March 23, 2008, 05:42 AMI don't think you'll find a crayon that's labeled "puke tan".  ;)

Heh.
EhPortal 1.34 © 2025, WebDev