[comp.sys.atari.st] vertical scrolling

jpdres13@usl-pc.UUCP (John Joubert) (06/03/88)

----------------

I remember someone a while back mentioned that you could do vertical
scrolling by using Setscreen() in increments of 256 bytes.  I have gotten
the scrolling to work, however, I had to use 256*5 or 1280 byte increments
in low rez in order to have the screen line up the left edge correctly.

Not surprisingly, for 32000 bytes I had to increment 25 times to do the 
whole screen. Funny how that is the EXACT number of lines on screen for low and
med rez!  I think that I have stumbled over a real fast way to do text 
scrolling!  Anyone out there tried this yet?

On a final note, I can only assume that the 256 byte increment will align
the screen correctly only in mono.  And since my mono monitor is on the
fritz ... can anyone tell me if the 256 byte increment will line up correctly
in mono?

----------------------------------------------------------------------------
John Joubert                         |     /\  |    /\    |     _ 
jpdres13@usl-pc.USL   or ...         |     \|<>|>|> \|<>|>|><`|`|
ut-sally!usl!usl-pc!jpdres13         |-----/|-------/|----------------------
GEnie: J.JOUBERT                     |     \/       \/
-----------------------------------------------------------------------------

dnewton@carroll1.UUCP (Dave 'Post No Nicknames' Newton) (11/13/89)

   How do ya' do vertical scrolling?  Do ya' just blit (VDI, not blitter) all
but the top/bottom line up/down, then fill in the new top/bottom line?  Or is
there a better way?

-- 
David L. Newton       | uunet!marque!carroll1!dnewton  | The Raging Apostle-- 
(414) 524-7343 (work) |    dnewton@carroll1.cc.edu     | for the future--
(414) 524-6809 (home) | 100 NE Ave, Waukesha WI 53186  | for the world.
"Isn't it fun to take two unrelated sentences and mix the batter lightly?" -me