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<!DOCTYPE concept
  PUBLIC "-//OASIS//DTD DITA Concept//EN" "concept.dtd">
<concept id="GUID-2559E3F7-314B-5DCC-A7FE-A08162A89721" xml:lang="en"><title>Local
Media Subsystem Overview</title><shortdesc>Provides the logical device driver for the internal and removable
storage media on a phone. </shortdesc><prolog><metadata><keywords/></metadata></prolog><conbody>
<section id="GUID-F7C4ED03-1A25-4F13-8B48-8A5463510422"><title>Purpose</title> <p>The local media sub-system allows the Symbian
platform file system and other programs to communicate with local media devices. </p> </section>
<section id="GUID-80F9C844-882C-4EA4-85C4-58D62C11685A"><title>Required background</title> <p>The local media sub-system
requires an understanding of the Symbian platform file system and local media
devices. </p> </section>
<section id="GUID-E70E10E5-2676-4C0F-B28B-060F823DECCF"><title>Key concepts and terms</title> <dl>
<dlentry>
<dt>local drive</dt>
<dd><p>A media drive mounted within the phone. </p> </dd>
</dlentry>
</dl> </section>
<section id="GUID-08F96B25-71FA-4A62-A77B-5076F509AE23"><title>Architecture</title> <p>The <xref href="GUID-32659A02-6541-3D15-AB88-B70FBD7DF9B0.dita"><apiname>TBusLocalDrive</apiname></xref> class
provides an interface to the local media sub-system. Each instance of this
class represents a channel of communication with a local drive. To establish
a channel a client connects an instance of the class to a specified drive.
The file server contains 16 instances of <xref href="GUID-32659A02-6541-3D15-AB88-B70FBD7DF9B0.dita"><apiname>TBusLocalDrive</apiname></xref>,
one for each local drive. Programs other than the file server may also create
instances to access a local drive. Drives are abstracted by the <xref href="GUID-2E1AEAC0-CEDF-31A5-B36A-FC4749B979A5.dita"><apiname>TDrive</apiname></xref> class. </p> </section>
<section id="GUID-3495E8DD-C6AA-47D3-A64F-4431C2A90850"><title>Local Media Sub-system Summary</title> <p>The local media
subsystem provides the following: </p> <ul>
<li id="GUID-79E68BE5-9713-5E24-B3C6-D0123CD13056"><p> <b>Local media LDD</b>  </p> <p> <filepath>elocd.ldd</filepath>  </p> <p>The
kernel-side logical device driver which implements communication between physical
devices and applications which use them. </p> </li>
</ul> </section>
<section id="GUID-74061F49-2659-47D1-9DB8-2FF3CB10B2E8"><title>Typical uses</title> <p>The <xref href="GUID-32659A02-6541-3D15-AB88-B70FBD7DF9B0.dita"><apiname>TBusLocalDrive</apiname></xref> class
is used to connect to and disconnect from local drives, to read to and write
from them, to provide information about the capabilities of the drives, to
format them, and to mount and remount drives on specified media drivers. </p> <p>Local
media subsystem: </p> <ul>
<li id="GUID-1A411257-57A7-5206-AE12-811B5F71727A"><p>Manages device connections </p> </li>
<li id="GUID-74C8A86A-D797-5473-8192-A4EA6DE1C8B0"><p>Manages data transfer </p> </li>
<li id="GUID-5D62718F-3B7F-5D0E-9B95-BDA2C1FB77D3"><p>Handles notifications
and device configuration. </p> </li>
</ul> </section>
</conbody><related-links>
<link href="GUID-F3BD37EC-0CCB-5859-908F-215E22C9FC20.dita#GUID-F3BD37EC-0CCB-5859-908F-215E22C9FC20/GUID-143780ED-4A23-5E72-A923-F605172EC8B5">
<linktext>File Server</linktext></link>
<link href="GUID-6CF2F4EF-383F-5850-A522-F425A83AA89E.dita#GUID-6CF2F4EF-383F-5850-A522-F425A83AA89E/GUID-20E09BC9-35CA-594A-BA91-D8D0C928FD98">
<linktext>File Systems</linktext></link>
<link href="GUID-9540A82E-F83D-55F5-B441-868CF77468E9.dita#GUID-9540A82E-F83D-55F5-B441-868CF77468E9/GUID-CFED15B1-E768-534E-9043-7AADE45EE9AF">
<linktext>Media Drivers</linktext></link>
</related-links></concept>