[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index]

Re: IIgs video modes...

Linards Ticmanis wrote:

bieling@terra.es wrote:



OTOH, if the image had exactly the same width, the pixels would have
to be shifted out at 7*1,1428=8.0 Mhz. or at 14*1.1428=15.999MHz.
These figures is quite suspicious... isn't it. So I'd say that the
image is probably of the same width if it were not because 8Mhz/16MHz
isn't an even multiple of the color carrier, and I guess that this,
from an NTSC point of view, may mess up the things a little bit. Or
not ?



Not necessarily... in the dark corners of the home computing world (i.e.
at Commodore) 8 MHz was the most common pixel clock. Their chips created
separate luma/chroma signals though, so the two clocks didn't have to
match up. I assume that the same is true for IIGS modes.


Apparently so.

In the personal computing world of the early 1980s, there were two
video "camps":  those who used the artifact color trick and those
who didn't.  One glance at the master clock frequency was usually
enough to tell the difference.  ;-)

-michael

NadaNet networking for Apple II computers!
Home page:  http://members.aol.com/MJMahon/

"The wastebasket is our most important design
tool--and it's seriously underused."