Re: Apple ][gs VGA Card

[jlee@ics.uci.edu (Orion Pax)]

Herbert Fung (herbertf@ersys.edmonton.ab.ca) wrote:
: Previously ntt@cleese.apana.org.au (Jonathan Pratt) wrote:
:  
: >Interlaced = the image is sent in two parts (theoretically more but I've
: >not seen it implemented).  The video signal represents half the screen
: >each time.  The hardware outputs the signal for alternate scan lines
: >(btw a scanline = one horizontal row of pixels) all the way down the
: >screen, and then the next cycle provides the ones in between which were
: >skipped last time.  This makes the screen update cycle half of the
: >original and can occasionally show picture abberations like flicker
: >(uncommon) or aliasing.
:  
: How does this help display higher resolution modes?

I think what happens is 200 lines are generated each scan so total, we can
get 400 lines in two scans.  But, it might be possible to do this with
overscan but I'm not sure how many lines overscan can do although it should
be more than 200 lines.

Joseph
--
jlee@clyde.ics.uci.edu   | Have you watched your Koko Wa GreenWood, Yotoden,
-------------------------+ Gundam 0083, Bubble Gum Crisis/Crash!, Video Girl
II(> Creative 'Ware <)II | Ai, Tenchi Miyou, Ah! My Goddess, Maison Ikkoku,
 Cal-Animage Epsilon VP  | PatLabor, Ranma 1/2, and Five Star Stories today?