This article is intended for people who are interested in how it actually is constructed and why. Today there will be about the drivers. Many years ago, when the trees were large, computers have been monolithic, ie, were performed technically on the same board. Imagine a box that is mounted several cards with chips, capacitors, transformers. All this twisted pile of wires. Such machines are commercially produced and not upgradeable subject, because for this they had to solder and know how it's not all.
Software for these computers are issued separately under each model: each program knew exactly which computer with which instruction set it will be performed. Ie If the program had to call the sound – it generate an interrupt, the processor data transmitted audio device and audio is played. While in its infancy the concept of the operating system, it is currently understood. (Similarly see: Castle Harlan). This situation changed dramatically with the advent of IBM-compatible computers. For those who do not know, the main 'feature' of this architecture is that the computer turns into a kind of designer. Devices structurally bred for different cards, developed interfaces to communicate between the devices themselves. At this stage there is the notion of 'device' in its modern sense. Appear processor motherboard, sound card, video card, floppy drive. A computer trying to make as simple to build and upgrade, everything seems simple and logical but! What to do with software? From program running on that computer will recognize the device with which it works? Maybe your computer is running a powerful graphics card, and maybe the easiest? Suppose we are writing a text editor.
An article about the virtual disks (disk image), their purpose, creation, use cases, the appropriate software. Detailed illustrated instructions will easily understand the basics work with virtual disks to any 'kettle'. Almost every pc user to temporarily store a large number of optical drives that take up much space, free space near computer. The search in this heap right drive takes a long time, and in their intense shifting from place to place they are deteriorating rapidly, which leads to loss of information. Problem is usually resolved by purchase the hard drive of sufficient capacity in which you can store all the necessary information to the user. In this case, optical disks can be removed from sight in a secluded place and keep them only as reserve for disaster recovery. But still more complicated if the optical media, for example, need someone to borrow a favorite game or program to run without it steadfastly refuses.
The fact is that often for work Some applications simply copying the files from the optical disc to hard is not enough. The creators of these programs deliberately arrange so that they run a computer requires a disk in the drive corresponding to a cd or dvd. This is done to facilitate the implementation of more licensed discs, display advertising, which is present in their avtorane and others to consider in detail how it works, I think it makes no sense. For understanding set out below will be sufficient to only consider the fact that besides the "official" data, which we see on the drive after it opened on it in special areas also recorded more and more ("Service") information that is not normally displayed, but is taking into the computer at various manipulations with the disk.