[Coco] Higher graphics mode (256 color mode?)

[Paul Wittkoski]

Hi everyone,

At one time, I found a higher graphics mode that is not documented with the
CoCo 3. It was 1024 pixels across and the pictures in pmode graphics could
be seen 4 times across the screen. I am unable to pull the exact method from
my computer since my 5.25" floppy drive blew a chip some time back. But,
someone may be able to find it again from what I remember what I did. It may
have been odd thinking at the time but I wondered if pmode and hscreen could
be used at the same time. Following the machine code for pmode and hscreen
in the unravelled series I found a specific poke to turn on pmode and
another one for hscreen. When I used them together on a cm-8 monitor it
produce a screen with 1024 pixel resolution across. I am not sure if this
would also lead to the 256 color mode if someone messed around with it.
Interesting enough, I have not ever heard anyone else describe what I have
done. Maybe that's how Tandy hid the 256 color mode so well; right under our
noses with pmode. I hope this information is useful to someone in some way
after all of these years.