Thursday, December 31, 2009

iPhone OS 3.1

The free iPhone OS 3.1 Software Update includes some great new features, as well as all the features from previous updates. iPhone OS 3.1 gives you Genius recommendations for apps, lets you download ringtones wirelessly, offers a new way to organize apps on your iPhone, and more.
Updating is easy. Learn how

How to install.

Step 1.

Make sure you are using the latest version of iTunes. Connect your iPhone to your computer.
Download iTunes

Step 2.

When iTunes opens, select your iPhone under Devices in the Source List on the left.

Step 3.

In the iPhone Summary pane, click Check for Update.

Step 4.

Click Download and Install. Do not disconnect your iPhone until the update has finished.

Genius Recommendations for Apps

Get recommendations for apps you might like based on apps you’ve already downloaded.

Genius Mixes

Have iTunes automatically create mixes based on what’s already in your library. You don’t even have to choose a sample song.1

Download Ringtones Wirelessly

Choose from thousands of iPhone ringtones on the iTunes Store and buy them with a tap.

Organize Apps in iTunes

Use iTunes on your computer to drag apps onto virtual Home screens, then sync them to your iPhone.

voice memo

Voice Memos

Capture a memo, a meeting, or any audio recording on the go. Voice Memos works with the built-in iPhone microphone or with the mic on your headset.
Calendar

Improved Calendar

Create meetings via Microsoft Exchange ActiveSync and subscribe to calendars with new CalDAV support.
itunes store

Buy Movies, TV Shows, and Audiobooks

Download movies, TV shows, music videos, and audiobooks from the iTunes Store on your iPhone.3
Stocks

Enhanced Stocks Application

Get more at-a-glance information and view charts in landscape.

iPhone OS 3.1 also includes these features from iPhone OS 3.0:

Cut, Copy, Paste and Landscape Keyboard MMS Spotlight Search

Cut, Copy & Paste

Quickly and easily cut, copy, and paste text from application to application. Select entire blocks of web text with a tap. Copy and paste images from the web, too.

Landscape Keyboard

Want more room to type? Rotate iPhone to landscape to use a larger keyboard in Mail, Messages, Notes, and Safari.

MMS

Send MMS messages and include photos, audio, and contact info.2 Even tap to snap a picture right inside Messages.

Spotlight Search

Find what you’re looking for across your iPhone, all from one place. Spotlight searches all your contacts, email, calendars, and notes, as well as everything in your iPod.

File system support in modern operating systems

Support for file systems is highly varied among modern operating systems although there are several common file systems which almost all operating systems include support and drivers for. Operating systems vary on file system support and on the disk formats they may be installed on.

 Mac OS X

Mac OS X supports HFS+ with journaling as its primary file system. It is derived from the Hierarchical File System of the earlier Mac OS. Mac OS X has facilities to read and write FAT, NTFS (read-only, although an open-source cross platform implementation known as NTFS 3G provides read-write support to Microsoft Windows NTFS file system for Mac OS X users), UDF, and other file systems, but cannot be installed to them. Due to its UNIX heritage Mac OS X now supports virtually all the file systems supported by the UNIX VFS..

 Solaris

The Solaris Operating System uses UFS as its primary file system. Prior to 1998, Solaris UFS did not have logging/journaling capabilities, but over time the OS has gained this and other new data management capabilities.
Additional features include Veritas (Journaling) VxFS, QFS from Sun Microsystems, enhancements to UFS including multiterabyte support and UFS volume management included as part of the OS, and ZFS (open source, poolable, 128-bit, compressible, and error-correcting).
Kernel extensions were added to Solaris to allow for bootable Veritas VxFS operation. Logging or journaling was added to UFS in Solaris 7. Releases of Solaris 10, Solaris Express, OpenSolaris, and other open source variants of Solaris later supported bootable ZFS.
Logical Volume Management allows for spanning a file system across multiple devices for the purpose of adding redundancy, capacity, and/or throughput. Solaris includes Solaris Volume Manager (formerly known as Solstice DiskSuite.) Solaris is one of many operating systems supported by Veritas Volume Manager. Modern Solaris based operating systems eclipse the need for volume management through leveraging virtual storage pools in ZFS.

 Linux

Many Linux distributions support some or all of ext2, ext3, ext4, ReiserFS, Reiser4, JFS , XFS , GFS, GFS2, OCFS, OCFS2, and NILFS. The ext file systems, namely ext2, ext3 and ext4 are based on the original Linux file system. Others have been developed by companies to meet their specific needs, hobbyists, or adapted from UNIX, Microsoft Windows, and other operating systems. Linux has full support for XFS and JFS, along with FAT (the MS-DOS file system), and HFS which is the primary file system for the Macintosh.
In recent years support for Microsoft Windows NT's NTFS file system has appeared in Linux, and is now comparable to the support available for other native UNIX file systems. ISO 9660 and Universal Disk Format (UDF) are supported which are standard file systems used on CDs, DVDs, and BluRay discs. It is possible to install Linux on the majority of these file systems. Unlike other operating systems, Linux and UNIX allow any file system to be used regardless of the media it is stored in, whether it is a hard drive, a disc (CD,DVD...), an USB key, or even contained within a file located on another file system.Microsoft Windows

Microsoft Windows currently supports NTFS and FAT file systems (including FAT16 and FAT32), along with network file systems shared from other computers, and the ISO 9660 and UDF filesystems used for CDs, DVDs, and other optical discs such as Blu-ray. Under Windows each file system is usually limited in application to certain media, for example CDs must use ISO 9660 or UDF, and as of Windows Vista, NTFS is the only file system which the operating system can be installed on. Windows Embedded CE 6.0, Windows Vista Service Pack 1, and Windows Server 2008 support ExFAT, a file system more suitable for flash drives.

 Special-purpose file systems

FAT file systems are commonly found on floppy disks, flash memory cards, digital cameras, and many other portable devices because of their relative simplicity. Performance of FAT compares poorly to most other file systems as it uses overly simplistic data structures, making file operations time-consuming, and makes poor use of disk space in situations where many small files are present. ISO 9660 and Universal Disk Format are two common formats that target Compact Discs and DVDs. Mount Rainier is a newer extension to UDF supported by Linux 2.6 series and Windows Vista that facilitates rewriting to DVDs in the same fashion as has been possible with floppy disks.

 Journalized file systems

File systems may provide journaling, which provides safe recovery in the event of a system crash. A journaled file system writes some information twice: first to the journal, which is a log of file system operations, then to its proper place in the ordinary file system. Journaling is handled by the file system driver, and keeps track of each operation taking place that changes the contents of the disk. In the event of a crash, the system can recover to a consistent state by replaying a portion of the journal. Many UNIX file systems provide journaling including ReiserFS, JFS, and Ext3.
In contrast, non-journaled file systems typically need to be examined in their entirety by a utility such as fsck or chkdsk for any inconsistencies after an unclean shutdown. Soft updates is an alternative to journaling that avoids the redundant writes by carefully ordering the update operations. Log-structured file systems and ZFS also differ from traditional journaled file systems in that they avoid inconsistencies by always writing new copies of the data, eschewing in-place updates. Graphical user interfaces
Most of the modern computer systems support graphical user interfaces (GUI), and often include them. In some computer systems, such as the original implementations of Microsoft Windows and the Mac OS, the GUI is integrated into the kernel.
While technically a graphical user interface is not an operating system service, incorporating support for one into the operating system kernel can allow the GUI to be more responsive by reducing the number of context switches required for the GUI to perform its output functions. Other operating systems are modular, separating the graphics subsystem from the kernel and the Operating System. In the 1980s UNIX, VMS and many others had operating systems that were built this way. Linux and Mac OS X are also built this way. Modern releases of Microsoft Windows such as Windows Vista implement a graphics subsystem that is mostly in user-space, however versions between Windows NT 4.0 and Windows Server 2003's graphics drawing routines exist mostly in kernel space. Windows 9x had very little distinction between the interface and the kernel.
Many computer operating systems allow the user to install or create any user interface they desire. The X Window System in conjunction with GNOME or KDE is a commonly-found setup on most Unix and Unix-like (BSD, Linux, Solaris) systems. A number of Windows shell replacements have been released for Microsoft Windows, which offer alternatives to the included Windows shell, but the shell itself cannot be separated from Windows.
Numerous Unix-based GUIs have existed over time, most derived from X11. Competition among the various vendors of Unix (HP, IBM, Sun) led to much fragmentation, though an effort to standardize in the 1990s to COSE and CDE failed for the most part due to various reasons, eventually eclipsed by the widespread adoption of GNOME and KDE. Prior to open source-based toolkits and desktop environments, Motif was the prevalent toolkit/desktop combination (and was the basis upon which CDE was developed).
Graphical user interfaces evolve over time. For example, Windows has modified its user interface almost every time a new major version of Windows is released, and the Mac OS GUI changed dramatically with the introduction of Mac OS X in 1999.

More on operating system

Microsoft Windows (OS)

Windows 7 Ultimate Desktop
Microsoft Windows is a family of proprietary operating systems that originated as an add-on to the older MS-DOS operating system for the IBM PC. Modern versions are based on the newer Windows NT kernel that was originally intended for OS/2. Windows runs on x86, x86-64 and Itanium processors. Earlier versions also ran on the Alpha, MIPS, Fairchild (later Intergraph) Clipper and PowerPC architectures (some work was done to port it to the SPARC architecture).
As of 2009, Microsoft Windows holds a large amount of the worldwide desktop market share. Windows is also used on servers, supporting applications such as web servers and database servers. In recent years, Microsoft has spent significant marketing and research & development money to demonstrate that Windows is capable of running any enterprise application, which has resulted in consistent price/performance records (see the TPC) and significant acceptance in the enterprise market.

Operating System

An operating system (OS) is an interface between hardware and user which is responsible for the management and coordination of activities and the sharing of the resources of a computer, that acts as a host for computing applications run on the machine. As a host, one of the purposes of an operating system is to handle the resource allocation and access protection of the hardware. This relieves application programmers from having to manage these details.
Operating systems offer a number of services to application programs and users. Applications access these services through application programming interfaces (APIs) or system calls. By invoking these interfaces, the application can request a service from the operating system, pass parameters, and receive the results of the operation. Users may also interact with the operating system with some kind of software user interface like typing commands by using command line interface (CLI) or using a graphical user interface. For hand-held and desktop computers, the user interface is generally considered part of the operating system. On large multi-user systems like Unix and Unix-like systems, the user interface is generally implemented as an application program that runs outside the operating system.
While servers generally run Unix or some Unix-like operating system, embedded system markets are split amongst several operating systems,[1][2] although the Microsoft Windows line of operating systems has almost 90% of the client PC market.
Operating systems Operating system placement.svg