Re: The Internet-enabled Contiki Desktop OS

[bill@newbreedsoftware.com (William Kendrick)]

In comp.sys.atari.8bit Andreas Berger <Andreas.Berger@de.bosch.com> wrote:
> Adam Dunkels wrote:
>> Contiki already runs on other architectures than the 65xx family: x86,
>> 68000, 6809 (I think).
> 
> ...what about using the 80 columns screen of the C128?

On the Atari 8-bit, you can get a fairly fast 80 column display by alternating
the display and the character set used.  (Sure, that adds another 2K to
what you're doing:  ~1K for the screen data, and 1K for the char. set,
but it works :^) )

FlickerTerm 80, a modem terminal program, is an excellent example.

Say you had the word "Computer" on the screen.

Frame 1, you display the first font (see below), and show this text:

  Cmue

Frame 2, you display the second font, and show this text:

  optr


The fonts are identical; 4 pixels wide by 8 pixels high.  One is just on
the left half, the other on the right:

  -------       --------
  -#-----       -----#--
  #-#----       ----#-#-
  #-#----       ----#-#-
  ###----  and  ----###-
  #-#----       ----#-#-
  #-#----       ----#-#-
  -------       --------

So between the two frames (ever 30th of a second), thanks to persistence
of vision, you get 80 columns.  Inverse-video is tricky, though. :^(


It's definitely faster than using 320x192 bitmap mode. :)

(Also, due to the slight timing difference, you can have 4-pixel-wide
letters, like "M" and "W" that are a bit less unreadable than if it weren't
flickering :^) )


-bill!

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