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From: Felton.pa@XEROX.COM
Newsgroups: net.micro.atari16
Subject: Re: Logbase/Physbase and Screen Dumps
Message-ID: <860421-105316-1612@Xerox>
Date: Mon, 21-Apr-86 13:53:15 EST
Article-I.D.: Xerox.860421-105316-1612
Posted: Mon Apr 21 13:53:15 1986
Date-Received: Wed, 23-Apr-86 22:00:52 EST
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>I believe that the screen dump routine should be using the
>physbase pointer, as all I have read implies that the screen
>dump capability should give you a printout of what is visible
>on the actual screen

>Have I found a bug?  Is there any way to fix it?

	No. You haven't found a bug. If you think about the reasoning behind
having two locations "logbase" and "physbase" you will see that it is
working properly. The ideas is to allow the programmer to perform page
flipping while using the system routines for writing to the screen. In
order for this to work you must display one screen but have the system
routines use another. Thus, there are two pointer, one points to the
memory which is to be displayed on the screen (physbase) the other to
the memory which is to be used by the system routines (logbase). If you
want the system routines to work on the currently displayed memeory then
you must set "logbase" to "physbase". If you started having system
routine use physbase then you would loose flexability (Printing one
screen while viewing another for example). To solve your problem simply
set "logbase" to "physbase" before calling the screen dump routine and
restore it after you return.
	
	
John