PCI, SCSI, and Fibre Channel

The PCI standard had its origins in the PC world, and has supplanted the two earlier standard microprocessor backplane buses�VME and Multibus. VME is, however, still used in real-time systems and in some process control applications. It started as a 16-bit bus and later grew to 32 bits; for the most part, VME-based systems used Motorola 68000-family microprocessors.Multibus I was also a 16-bit bus initially, but Multibus systems tended to house Intel processors. While Intel extended the definition of Multibus I to 32 bits as Multibus II, the new version never saw wide adoption and disappeared fairly quickly.We can summarize PCI�s major characteristics as follows:� Two data transfer widths�32 bits and 64-bits� Two clock rates�33MHz and 66MHz� Various available bandwidths (133, 266, and 532...

Understanding 64-Bit Computing

Since it was introduced for Windows operating systems, 64-bit computing has changed substantially. Not only do computers running 64-bit versions of Windows perform better and run faster than their 32-bit counterparts, they are also more scalable because they can process more data per clock cycle, address more memory, and perform numeric calculations faster. Windows 7 supports two different 64-bit architectures:� x64 This architecture is based on 64-bit extensions to the x86 instruction set, which is implemented in AMD Opteron (AMD64) processors, Intel Xeon processors with 64-bit extension technology, and other processors. This architecture offers native 32-bit processing and 64-bit extension processing, allowing simultaneous 32-bit and 64-bit computing.� ia64 This architecture is based on...

I/O

Neither systems architects nor computer architecture researchers have paid as much attention to I/O as they have to processors. The rationale for this lack of attention is completely unclear to us, since I/O is a key part of a system, being both a driver for system performance and an opportunity for value add�unlike processors, where the economies of scale predominate. We provided a generic server model with the purpose of identifying the various interconnects of interest, mentioning the interconnects between processor, memory and I/O.An I/O system comprises a number of elements.As shown in this diagram, the various elements of a classical I/O subsystem are as follows:� A system controller implementing the connection between processor(s), memory and the I/O bus(es). In practice, this is often...

Naked Gaming

Good-bye, controller: an Xbox upgrade reads natural gesturesWhen Nintendo�s Wii game console debuted in November 2006, its motion-sensing handheld �Wiimotes� got players off the couch and onto their feet. Now Microsoft hopes to outdo its competitor by eliminating the controller altogether: this past January it revealed details of Project Natal, which will give Xbox 360 users the ability to manipulate on-screen characters via natural body movement. The machine-learning technology will enable players to kick a digital soccer ball or swat a handball simply by mimicking the motion in their living room.Microsoft, which announced its ambitious Xbox upgrade plan in June 2009, has not set a release date, but many observers expect to see Natal at the end of the year. It will consist of a depth sensor...

Fedora 12 Enabling Authentication

In most situations, you will enable shadow passwords and SHA512 passwords (as selected by default) to authenticate users who log in to your computer from local passwd and shadow password files. To change that behavior, you can select the Use Network Login button during the Create User setup during Firstboot.The shadow password file prevents access to encrypted passwords. SHA512 is an algorithm used to encrypt passwords in Linux and other UNIX systems. It replaces an algorithm called crypt, which was used with early UNIX systems. When you enable SHA512 passwords, your users can have longer passwords that are harder to break than those encrypted with crypt. You can also use MD5 or SHA256 for encrypting passwords, although these methods are less secure.If you are on a network that supports one...

Fedora 12 Choosing Different Install Modes

Although most computers automatically install Fedora in the default mode (graphical), there may be times when your video card does not support that mode. Also, although the install process will detect most computer hardware, there may be times when your hard disk, Ethernet card, or other critical piece of hardware cannot be detected and you�ll need to enter special information at boot time.The following is a list of different installation options you can use to start the Fedora install process. You would typically try these modes only if the default mode failed (that is, if the screen was garbled or installation failed at some point). For a list of other supported modes, refer to the /usr/share/doc/anaconda*/command-line.txt file (if you have a running Fedora system somewhere with the anaconda...

Choosing computer hardware to Install Fedora 12

This may not really be a choice. You may just have an old PC lying around that you want to try Fedora on. Or you may have a killer workstation with some extra disk space and want to try out Fedora on a separate partition or whole disk. To install the 32-bit PC version of Fedora successfully (that is, the version on the accompanying DVD), the computer must have the following:� x86 processor � Your computer needs an Intel-compatible CPU. With the latest version, Fedora recommends that you at least have a Pentium-class processor to run Fedora. For a text-only installation, a 200 MHz Pentium is the minimum, while a 400 MHz Pentium II is the minimum for a GUI installation.� DVD or CD-ROM drive � You need to be able to boot up the installation process from a DVD, CD-ROM, or other bootable drive....

Install Fedora 12 From DVD, network, or hard disk?

When you install Fedora, the distribution doesn�t have to come from the installation DVD or CD. After booting the installation DVD, press Tab with the Install selection highlighted. Then type the word askmethod at the end of the boot command line displayed and press Enter. You are offered the choice of installing Fedora from the following locations:� Local DVD or CDROM � This is the most common method of installing Fedora and the one you get by simply pressing Enter from the installation boot prompt. � Hard drive � If you can place a copy of the Fedora distribution on your hard drive, you can install it from there. (Presumably, the distribution is on a hard drive partition to which you are not installing.)� NFS directory � Allows you to install from any shared directory on another computer...

Fedora 12 selecting Install or upgrade?

First you should determine if you are doing a new install or an upgrade. If you are upgrading an existing Fedora system to the latest version, the installation process will try to leave your data files and configuration files intact as much as possible. You also need to do the upgrade from the DVD because upgrades are not available from the Fedora live CD.An upgrade installation takes longer than a new install. A new install will simply erase all data on the Linux partitions (or entire hard disk) that you choose. (You can optionally select which partitions to format.)If you choose to upgrade, you can save yourself some time (and disk space) by removing software packages you don�t need. An upgrade will just skip packages that are not installed and not try to upgrade them. Here are a few other...

Fedora 12 Quick Installation

If you have a little bit of experience with computers and a computer with common hardware, you can probably install Fedora pretty easily. The procedure in this section will get you going quickly if you have:� Media � The Fedora installation DVD or live/install CD � PC � A Pentium-class PC (at least 200 MHz for text mode; 400 MHz Pentium II for GUI) with a built-in, bootable DVD or CD drive, at least 128MB of RAM (for text mode) or 256MB of RAM (for GUI mode).� Disk space � If you are installing from the live CD, you need at least 3GB of disk space. Keep in mind that the live CD install only copies the live CD files to your hard disk. You don�t get to select individual packages, as you do when installing from the DVD. (The fact that files are compressed on the CD accounts for the need for more...

One Small Step for Intellectual Property

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Using the Fedora 12 Live CD

The official Fedora 12 Desktop Live CD is a great way to try out Fedora before you commit to installing it. In addition to answering the obvious question of �does Fedora run on my PC at all?� the CD itself contains useful tools for examining your hardware and preparing your computer for installation.USB flash drives can be used the same way) that contains an entire operating system. In most cases, you can boot the live CD without touching the contents of your hard drive. With the Fedora 12 Desktop Live CD, you can boot up to a working GNOME desktop that works like most desktop computer systems installed to hard disk. If you don�t like the system, then reboot, remove the CD, and your computer will return to the way it was. If you like it, you can click a single button and install the same desktop...

Understanding Fedora Installation Media

The Fedora project includes a lot of software to help you get started installing the release as well as creating your own releases, if you desire. These include:� Fedora Repository � This repository, maintained by the Fedora Project, includes all the software.� Installation Media � The Fedora repository contains too much software to expect the average person to download. Therefore the Fedora Project offers more reasonable-sized installation media that include a single 3.5G installation DVD, a GNOME Desktop Live CD, and a KDE Desktop Live CD. Either of the live CDs can also be used to install the Fedora desktop system contained on that CD to hard drive. You can also download the equivalent of the installation DVD as a set of five CDs if you don�t have a writable DVD drive. See http://fedoraproject.org/en/get-fedora-all...

The Culture of Free Software

Fedora was born from a culture of free software development and continues to thrive from that culture. The copyright for software included in Fedora systems is covered primarily under the GNU public license. That license, which most free software falls under, provides the following:� Author rights � The original author retains the rights to his or her software.� Free distribution � People can use the GNU software in their own software, changing and redistributing it as they please. They do, however, have to include the source code with their distribution (or make it easily available).� Copyright maintained � Even if you were to repackage and resell the software, the original GNU agreement must be maintained with the software. This means that all future recipients of the software must have...