[Coco] Sock unveils his CoCo mystery!

[John Kowalski]

First off, thanks again to everybody for the wonderful response and comments!

Richard,

I had actually considered doing a version for vertical monitors too.  (Would
someone want to put a CoCo into an arcade cabinet to run Donkey Kong??)  In
the end I decided on one version that everyone would be able to play - no
6309, no having to rotate the monitor :)

To rotate, the graphics routines would need to be rewritten, and the
graphics data itself entirely redone, but it would have been possible.
Much later on, I did realise there would have been some complications.  To
get maximum performance, the code takes some shortcuts and doesn't bother to
fully mask out stray individual pixels in the sprites - if you look
carefully, you can spot some black pixels beside mario/fireballs/etc when
they're drawn in front of other objects.  If it were rotated, these
occasional black pixels would appear above and below some sprites rather
than on their left & right edges.  Black pixels below Mario would mean they
would sometimes appear under his feet and blank out parts of the girders
he's walking on!  It would still work, but this particular graphical glitch
would be much, *much* more noticable then, maybe even to the point of being
distracting.

Of course, it could still then be possible to just add the extra masking to
fix this.  The extra processing would impact performance a bit, but still work.


At 04:48 PM 02/04/2007 +0100, CoCoList for Color Computer Enthusiasts wrote:
>Sock,
>
>Great job! I'm particularly impressed by the music - how you get it to run
>smoothly along with the rest of the game is beyond me.
>
>Regarding the aspect ratio, would it be possible to do a vertical
>orientation version in 256x225 which required the user to turn their monitor
>/ TV by 90 degrees? I know this affects the video memory accesses in a big
>way so it would be a quite different piece of code, just wondered what your
>thoughts on this were.
>
>Richard

                                         John Kowalski (Sock Master)
                                         http://www.axess.com/twilight/sock/