[Coco] Re: again: CoCo RGB to VGA conversion

Mark Marlette mmarlett at isd.net
Mon Aug 23 22:43:35 EDT 2004


At 8/23/2004 10:24 PM -0400, you wrote:

james,

Honestly I can say not really. My focus was Computer Systems, two year 
degree. That is it. I graduated top of my class of 125 and didn't hardly 
try....Sad to say the rest was at the school of hard knocks.

Have/had my test applications running at the largest electronics 
manufacture in the world, Delphi Electronics and the other two big car 
manufactures, Ford and Chrysler. Now I'm just a Test Engineer for a Defense 
Contractor, very little TV, just BIG guns and cannons! Remember the 
Crusader tank? I was lead ATE Test Engineer on that project. Sad how the 
government can kill such technology and NOTHING in this world would have 
even come close to that tank. Over $2BILLON down the tubes......Was an 
awesome sight on how something 50tons could be lifted when it fires and 
could moved on land at +45MPH!

Back to fun stuff....CoCo!

Regards,

Mark






>VGA specs are th is
>
>2 lines front porch
>2 lines sync
>25 lines back porch
>8 lines top border
>8 lines bottom border
>
>480 lines display
>
>total 525
>
>sound familiar?
>
>james
>
>On 23 Aug 2004 at 21:09, Mark Marlette wrote:
>
>Date sent:              Mon, 23 Aug 2004 21:09:34 -0500
>To:                     CoCoList for Color Computer Enthusiasts
><coco at maltedmedia.com>
>From:                   Mark Marlette <mmarlett at isd.net>
>Subject:                Re: [Coco] Re: again: CoCo RGB to VGA
>conversion
>Send reply to:          CoCoList for Color Computer Enthusiasts
><coco at maltedmedia.com>
>         <mailto:coco-
>request at maltedmedia.com?subject=unsubscribe>
>         <mailto:coco-
>request at maltedmedia.com?subject=subscribe>
>
> > At 8/24/2004 01:45 AM +0000, you wrote:
> >
> > I would not add the composite mode into it......
> >
> > Garbage in....garbage out. Keep cost down, RGB only.
> >
> > I would have to review my TV course text book but you have vertical
> > blanking which accounts for x number of lines. Heck that was 20 years
> > ago.......
> >
> > My approach would have a line counter so that you could double or run
> > original size vertically.
> >
> > Someone here will probably beat me to this project. Too many other
> > CoCo projects in front of this one. Hardware talent all around. lets
> > get some more software development going!
> >
> > Can someone make more hours in a day? I'll buy a couple.... :)
> >
> > Mark
> > Cloud-9
> >
> >
> >
> > > > > It's hard for a converter to scale up a line to a fraction of a
> > > > > line, such as 1.5 lines (without some significant gray-level
> > > > > anti-aliasing). Let's see, the VGA has 480 lines.  Straight
> > > > > Coco3 has 384, or 80%, so you have 10% of the total screen
> > > > > height blank at top and bottom.  Not too bad. RSBASIC and maybe
> > > > > even OS-9 can be poked up to 200 high, or 400 out of 480. Some
> > > > > BASIC hackers claim to have hit 225, or 450 out of 480.
> > >
> > >Where does the 384 come from? Is that vertical padding? With 225
> > >lines to work with, that's 159 extra lines. Right? So the ideal thing
> > >for this conversion hardware to do, would be to snip out those 159
> > >blank scan lines, and mutliply the usable 225 by a nice integer,
> > >namely 2. That would produce 450 scan lines, with a margin of 30
> > >lines to fit within a 480 line screen. Piece of cake! :-)
> > >
> > >Oh, and a switch to choose either the analog RGB signal or the
> > >composite signal would be nice. That way, users could have the best
> > >of both worlds, RGB for most apps, and composite for software which
> > >uses artifacting.
> > >
> > >David
> > >
> > >
> > >--
> > >Coco mailing list
> > >Coco at maltedmedia.com
> > >http://five.pairlist.net/mailman/listinfo/coco
> >
> >
> >
> > --
> > Coco mailing list
> > Coco at maltedmedia.com
> > http://five.pairlist.net/mailman/listinfo/coco
>
>
>
>--
>Coco mailing list
>Coco at maltedmedia.com
>http://five.pairlist.net/mailman/listinfo/coco





More information about the Coco mailing list