Subject: Re: dots and black background
From: Jim Murphy <[email-masked]>
Date: Wed, 15 Sep 1993 20:29:39 GMT
Newsgroups: comp.sys.apple2.programmer

In article <[email-masked]> Bright Software,
[email-masked] writes:
> Since it's pretty safe toi assume that Superhires _is_ and _will be_ at
> $E12000, you might want to convert local coordinates to global ones,
> calculate the screen address and then read-modify-write video ram
>
> NOTE: this method is not Apple approved. By writing directly to video
> RAM you're violating and breaking almost all of Apple's
> guidelines/rules. 

     Well, you don't have to be nearly as paranoid as you'd think. If you
want to draw directly to the screen, simply open a GrafPort, and look at
the ptrToPixImage field. This will always point to whatever location is
correct to get your image to the screen. In the case of having Close View
installed, this points to the shadow RAM in bank $01. If you use the
GrafPort as your friend, drawing directly to the screen is pretty easy.
You should also take into account the bounds of this area, as well as the
length in bytes of each row. These, too, are described by various values
in the GrafPort.

     And we've never said don't draw directly to the screen. You just have
to be friendly with the toolbox to do it. Simple.

Jim Murphy                                                 [email-masked]

"...never quite said what I wanted to say to you,                 The Cure
  never quite managed the words to explain to you..."             Untitled