April 17, 2008

What are the device drivers?

A device driver, or a software driver is a type of computer software, typically developed to make the hardware in your computer work. Typically this constitutes an interface for communicating with the device, through the specific computer bus or communications subsystem that the hardware is connected to, providing commands to and/or receiving data from the device, and on the other end, the requisite interfaces to the operating system and software applications. Often called a driver for short, it is a specialized hardware dependent computer program which is also operating system specific that enables another program, typically an operating system or applications software package or computer program running under the operating system kernel, to interact transparently with a hardware device, and usually provides the requisite interrupt handling necessary for any necessary asynchronous time-dependent hardware interfacing needs.

Device driver theory
The key design goal of device drivers is abstraction. Every model of hardware (even within the same class of device) is different. Newer models also are released by manufacturers that provide more reliable or better performance and these newer models are often controlled differently.

Computers and their operating systems cannot be expected to know how to control every device, both now and in the future. To solve this problem, operating systems essentially dictate how every type of device should be controlled. The function of the device driver is then to translate these OS mandated function calls into device specific calls. In theory a new device, which is controlled in a new manner, should function correctly if a suitable driver is available. This new driver will ensure that the device appears to operate as usual from the operating systems' point of view.

Depending on the specific computer architecture, drivers can be 8-bit, 16-bit, 32-bit, and more recently, 64-bit. This corresponds directly to the architecture of the operating system for which those drivers were developed. For example, in 16-bit Windows 3.11, most drivers were 16-bits, while most drivers for 32-bit Windows XP are 32-bit. More recently, specific 64-bit Linux and Windows versions have required hardware vendors to provide newer 64-bit drivers for their devices.

Device driver development
Writing a device driver is considered a challenge in most cases, as it requires an in-depth understanding of how a given platform functions, both at the hardware and the software level. Because many device drivers execute in kernel mode, software bugs often have much more damaging effects to the system. This is in contrast to most types of user-level software running under modern operating systems, which can be stopped without greatly affecting the rest of the system. Even drivers executing in user mode can crash a system if the device being controlled is erroneously programmed. These factors make it more difficult and dangerous to diagnose problems.

All of this means that the engineers most likely to write device drivers come from the companies that develop the hardware. This is because they have more complete access to information about the design of their hardware than most outsiders. Moreover, it was traditionally considered in the hardware manufacturer's interest to guarantee that their clients would be able to use their hardware in an optimum way. However, in recent years non-vendors too have written numerous device drivers, mainly for use under free operating systems. In such cases, co-operation on behalf of the vendor is still important, however, as reverse engineering is much more difficult with hardware than it is with software, meaning it may take a long time to learn to operate hardware that has an unknown interface.

In Windows, Microsoft is attempting to address the issues of system instability by poorly written device drivers by creating a new framework for driver development known as Windows Driver Foundation (WDF). This includes UMDF User Mode Driver Framework that encourages development of certain types of drivers – primarily those that implement a message-based protocol for communicating with their devices – as user mode drivers. If such drivers malfunction they will not cause system instability. The KMDF Kernel Mode Driver Framework model continues to allow development of kernel-mode device drivers, but attempts to provide standard implementations of functions that are well known to cause problems, including cancellation of I/O operations, power management, and plug and play device support.

Device driver applications
Because of the diversity of modern hardware and operating systems, many ways exist in which drivers can be used. Drivers are used for interfacing with:

Printers

Video adapters

Network cards

Sound cards

Local buses of various sorts – in particular, for bus mastering on modern systems

Low-bandwidth viagra 100mg tablets I/O buses of various sorts (for pointing devices such as mice, keyboards, USB, etc.)

computer storage devices such as hard disk, CD-ROM and floppy disk buses (ATA, SATA, SCSI)

Implementing support for different file systems

Implementing support for image scanners and digital cameras

Choosing and installing the correct device drivers for given hardware is often a key component of computer system configuration.

Virtual device drivers
A particular variant of device drivers are virtual device drivers. They are used in virtualization environments, for example when an MS-DOS program is run on a Microsoft Windows computer or when a guest operating system is run inside e.g. VMware. Instead of enabling the guest operating system to dialog with hardware, virtual device drivers take the opposite role and emulate a piece of hardware, so that the guest operating system and its drivers running inside a virtual machine can have the illusion of accessing real hardware. Attempts by the guest operating system to access the hardware are routed to the virtual device driver in the host operating system as e.g. function calls.

The virtual device driver can also send simulated processor-level events like interrupts into the virtual machine.

Permalink • Print • Comment

DriverMax

Have you ever formatted your hard drive and installed a fresh copy of Windows? I know I have several times. Everyone will have to go through that process from time to time and it can be quite a hassle. Well, today, I have a free download for you that will save you a ton of time the next time you need to reinstall Windows. The program is called DriverMax and it will eliminate some of your worst headaches!

DriverMax does something that I have never seen before. It can create an archive of all your device drivers. By doing that, you don't have to worry about hunting down disks and downloads for all of viagra 100mg dosage the hardware on your computer. You simply run DriverMax, click Export Drivers, select the drivers you want to backup and then let it work its magic. DriverMax will save all of those hard to find device drivers for you in one folder. You can then store them on a flash drive or burn them to a disk so that you will never have to search for them again!

Then after you format and reinstall Windows, simply insert the disk or flash drive that holds your drivers. You can then tell your computer to look on the flash drive or CD for the missing drivers. If you want to make it even easier on yourself, you can reinstall DriverMax on your computer after you're done and have it install the drivers for you. After installing DriverMax, simply click Import and tell it where to locate the drivers file. It will then handle the rest!

I love this program and I only wish I would have found it sooner. It would have saved me so much time!

You can read more about DriverMax and download it for yourself right here.

Note: This program has a free registration process. You will be required to provide an e-mail address to be able to access the program. Also, it's compatible with Windows XP and Vista only. Enjoy!

Permalink • Print • Comment

Prevent a shutdown of a Windows XP system

Date: April 16th, 2008

Author: Greg Shultz

By default, at three o’clock every morning Windows XP’s Automatic Updates tool contacts the Windows Update site and automatically downloads and installs updates for your system. However, that cannot happen if other people who use the computer shut it down at the end of the day. Fortunately, you can prevent anyone from shutting down Windows XP with a little registry tweak. Here’s how:

  1. Launch the Registry Editor (Regedit.exe).
  2. Go to HKEY_CURRENT_USER\ SOFTWARE\Microsoft\Windows\CurrentVersion\Policies\Explorer.
  3. Right-click the Explorer subkey and select New | DWORD Value.
  4. Name the key NoClose and press [Enter] twice.
  5. Type 1 in the Value Data text box and click OK.

To enable the setting, close the Registry Editor and restart your system. Once your system restarts, you will not be able to it shut down by clicking the Shutdown button on the Start menu. This will prevent most users from inadvertently shutting down the computer.

When you do want to shut down your system, just access Task Manager by pressing [Ctrl][Alt][Del], then pull down the Shut Down menu and select the Turn Off command.

Note: Since editing viagra 100 mg dose the registry is risky, be sure you have a verified backup before saving any changes. This tip applies to both Windows XP Home and Windows XP Professional.

Permalink • Print • Comment

Thieves caught out as PCs ‘phone home’

Nick Heath

15 Apr 2008 09:14 BST

Computers that 'phone home' after being stolen are guiding police to the doorsteps of thieves across the world.

Tracking technology has helped police sniff out thousands of stolen machines, uncovering UK computers as far away as Argentina, Macedonia and Saudi Arabia.

West Midlands Police recently used the technology to make arrests and recover more than 30 laptops.

Alan McInnes, general manager with the Association of Chief Police Officers crime prevention initiatives, told ZDNet.co.uk's sister site, silicon.com, that the technology will help stamp out computer theft.

McInnes said: "The more widely this technology is used, the more the risk goes up and the more it will devalue the attractiveness of computer theft. This tracking technology has already proven itself useful for recovering large numbers of cars, its success rate is about 95 percent, and we hope it will do the same for computers. You not only recover the stolen property you are looking for, you often will uncover more stolen property and other related crimes."

The most effective type of tracking software is buried within the bios of a computer's motherboard during manufacture, making it resistant to hard disk wiping or removal.

When a stolen machine is connected to the internet it will contact a monitoring centre to report its IP address, allowing police to trace its location through the internet service provider.

usa viagra

Absolute Software claims its tracking and recovery software solution, ComputraceOne, has recovered more than 5,000 stolen computers worldwide.

Permalink • Print • Comment
Made with WordPress and an easy to customize WordPress theme • Sky Gold skin by Denis de Bernardy