[Coco] hardware scrolling

[John W. Linville]

On Sun, Dec 01, 2013 at 12:18:35AM -0800, Steve Bjork wrote:

> The other problem, some of the tricks we found were not allowed to
> be used in software we sold to Tandy,  Why?  Tandy wanted make sure
> the old software worked on new versions of the CoCo.  As you know,
> some software that uses semi-graphics don't work on the CoCo 3
> because that semi-graphics mode was not supported.  Think Plug &
> Power controller software for one.

At what point did Tandy officially start to warn people not to use
the SG-8/12/24 semi-graphics modes?  Obviously they aren't supported
in the GIME, but that would come been several years later.  Was there
any other reason for Tandy to not want people to use those modes?

Some claim that those modes are 'undocumented', but they are clearly
described in the SAM datasheet.  I'm curious to why Tandy would
have actively discouraged use of the Color Computer's most colorful
video modes.  Any evidence-based (i.e. not just conjecture) on the
matter would be most welcome for some research I've been doing...

John
-- 
John W. Linville		Someday the world will need a hero, and you
linville at tuxdriver.com			might be all we have.  Be ready.