add DIO section

git-svn-id: svn://svn.cc65.org/cc65/trunk@3398 b7a2c559-68d2-44c3-8de9-860c34a00d81

diff --git a/doc/atari.sgml b/doc/atari.sgml
index bd141527e03fd4aae13acbeceadef76942ae7363..cc5bf26f945034c87f6c885064f364c1431e9251 100644 (file)
--- a/doc/atari.sgml
+++ b/doc/atari.sgml
@@ -185,6 +185,15 @@ platform. There is a static driver you can use.
 <sect>Limitations<p>
 
 
+<sect>DIO implementation<label id="dio"><p>
+
+The Atari supports disk drives with either 128 or 256 byte sectors.
+The first three sectors of any disk are always 128 bytes long though. This is
+because the system can only boot from 128 bytes sectors.
+
+Therefore the DIO read and write functions transfer only 128 bytes
+for sectors 1 to 3, regardless of the type of diskette.
+
 
 <sect>Other hints<p>
 
@@ -192,7 +201,7 @@ platform. There is a static driver you can use.
 
 These are defined to be Atari + number key.
 
-<sect1>Reserving a memory area inside the program<label id="memhole"><p>
+<sect1>Reserving a memory area inside a program<label id="memhole"><p>
 
 The Atari 130XE maps its additional memory into CPU memory in 16K
 chunks at address &dollar;4000 to &dollar;7FFF. One might want to
@@ -226,10 +235,10 @@ header must be discarded. It will be replaced by a user created
 one.
 <p>
 The user needs to create a customized linker config file which adds
-new memory areas and segments to hold the new EXE header and added
-load chunk header data. Also an assembly source file needs to be
-created which defines the contents of the new EXE header and the
-second load chunk header.
+new memory areas and segments to hold the new EXE header and the
+header data for the second load chunk. Also an assembly source file
+needs to be created which defines the contents of the new EXE header
+and the second load chunk header.
 <p>
 <p>
 This is a modified cc65 Atari linker configuration file (split.cfg):