Path: utzoo!utgpu!jarvis.csri.toronto.edu!mailrus!cornell!uw-beaver!tektronix!reed!psu-cs!bartonr
From: bartonr@psu-cs.UUCP (Robert Barton)
Newsgroups: comp.sys.amiga.tech
Subject: Introduction to comp.sys.amiga.tech
Message-ID: <1739@psu-cs.UUCP>
Date: 7 Mar 89 03:04:54 GMT
Reply-To: bartonr@psu-cs.UUCP (Robert Barton)
Organization: Dept. of Computer Science, Portland State University; Portland OR
Lines: 20

> # 4 : The Amiga's custom graphics and sound chips can only access the
> first 512K of memory (slow or chip memory). Therefore, anything that
> these chips use must be in the first 512K of memory. This includes
> Window, Gadget and BitMap structures that Intuition uses. To make sure
> that you get chip memory do add the MEMF_CHIP constant to your call to
> malloc:
>
>       foobar *milkchocolate;
>       milkchocolate = ( foobar * ) AllocMem (sizeof(foobar), MEMF_CHIP);
>
> Then copy your data to the memory pointed to by "milkchocolate". 
>
> Edwin Hoogerbeets
> uunet!utai!utcsri!hcr!edwin

  This is a new one to me.  When the OpenWindow() routine allocates the
memory for the Window structure it asks for MEMF_CLEAR | MEMF_PUBLIC.  Same
with OpenScreen() when allocating a Screen or RasInfo structure.  Since a
Screen contains a ViewPort, a RastPort, a BitMap, and a LayerInfo this
implies that none of these structures need to be in chip memory either.