[Coco] CoCo2 Strange Side Switches

[Bill Pierce]

John the "2b"" was Tandy's last Coco 2. It featured an enhanced version of the VDG chip that allowed true lower case instead of "reverse text". The only problem was Tandy made no provisions to use it. 
When used, it seemed like a normal Coco 2. But with a poke or 2, it could do lower case, but it would reset constantly so it took a hardware hack to make the lower case constant. There were several articles in Rainbow about this Coco right before the Coco 3 came out in 86.
 

Bill Pierce
"Today is a good day... I woke up" - Ritchie Havens
 

My Music from the Tandy/Radio Shack Color Computer 2 & 3
https://sites.google.com/site/dabarnstudio/
Co-Contributor, Co-Editor for CocoPedia
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E-Mail: ooogalapasooo at aol.com


 
 
-----Original Message-----
From: John Goerzen <jgoerzen at complete.org>
To: coco <coco at maltedmedia.com>
Sent: Thu, Dec 4, 2014 11:03 pm
Subject: Re: [Coco] CoCo2 Strange Side Switches


Louis Ciotti <lciotti1 at ...> writes:

> 
> Can you verify where each wire really goes?  from prior posts we know one
> goes to the second pin down from the upper right.  Maybe some better photos.

I opened it back up, and took photos from a more helpful angle.  I added
them to the gallery here:

https://www.dropbox.com/s/avmph8x7oykd222/coco-switches.jpg?dl=0

I think IMG_4377 shows what's going on.  On the second leg down from the top
on the big chip, they cut the leg.  Two wires are soldered onto the leg from
the chip, and one onto the leg going into the socket (the one coming in
underneath).

On the smaller ship, it seems to be wired to the upper right.

I wonder if any of this has impact on the fact that everything that comes
out of it video-wise is brown.

> I wonder if this is a mod that is just wired wrong...  Is this a CoCo 2b
> with real lower case?  Seems like this would be the green border and the
> true lower can mods

I don't know what a 2b is, but I can say:

My original CoCo that my parents bought for me in the 80s was model number
26-3127.  The one I just got off eBay is 26-3136a.  There is a photo of the
back side of both in the set now.  The one with the cables hooked up is my
original, and the one without the cables is the one I just god.

Thanks!

John

> 
> On Wed, Dec 3, 2014 at 11:53 AM, John Goerzen <jgoerzen <at> complete.org>
wrote:
> 
> > Luis Antoniosi (CoCoDemus <retrocanada76 <at> ...> writes:
> >
> > >
> > > I would bet on the 2 more "famous" switches:
> > >
> > > 1 - reverse video
> > > 2 - pause
> >
> > I went ahead and fired it up.
> >
> > And, well, they both seem to have something to do with video.  But it's
> > very
> > strange.
> >
> > This thing seem to only emit shades of brown.  The default screen is black
> > on sort of tan instead of black on green.  The block cursor seems to
> > color-shift slower, because I suspect it is mapping some colors to shades
> > of
> > brown.  It only shows three colors (near-black, medium, and light).
> >
> > The switches do impact it.  One switch makes the default screen darker, and
> > depending on the position of the first switch, the second either does
> > nothing, or makes a wavy region of darker background appear.  Stumped, I
> > am.
> >
> > John
> >


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