The most popular mainframes are those which are manufactured by the IBM. They are the large systems which they started producing them in 1952 and are successful till date. Today the IBM mainframe means the systems which have the basic design of the IBM system/360 model. The IBM system/360 model was the compact model which could be used both for the scientific and the business purpose. It has been named system/360 to state that it includes all the aspect of the computer system i.e. 360 degrees. It had systems which were both upward and downward compatible. Also they had protection for the memory which could provide the security to your data. The newer versions of the mainframes have the extended addressing schemes to 24 bits from 18 bits. After the system/360 mainframes many others were developed which are system/370 and the system/390. The virtual memory concept was first introduced in the system/370 models.
The mainframes have been continuously evolving since they were developed. They have their own different characteristics which make them different from the others. They are capable of running more than one operating systems in one. This allows the virtual concept to function in the mainframes. The mainframes were the first to bring in virtual concept which was later incorporated in the other systems. Two levels of virtualization are available which are the virtual machines and the logical partitions. They also provide the facility for backup for the customers. They generally have two machines one for the work and other one for the backup which can help in case of any failure. It has good scaling ability, can manage heavy workloads, also reduces the cost of the labor and is known for giving the uninterrupted service to the users. They also have the characteristics to deal with the fault tolerance very well.
A steady growth of mainframes means that they have a good future as well. But there are certain things which must be known about the mainframes before considering them. To manage your organization with the mainframes you need a huge investment and money. Also many technologies may develop which are against the mainframes. The immediate use of those technologies may be very difficult while you are using the mainframes. Mainframes have large skills and features which have to be known before operating it. So people who are skilled enough to work on the mainframes have to be selected for handling them. It is seen that the mainframes due to their high cost and technology small scale markets cannot get the technology installed in their business. But apart from these factors many organization use the mainframes and its future is predictable good. There are about 10000 organizations that are using the mainframes to operate their business. The career in mainframes is good as it is most demanding field now. But as the year passes it is seen that the skills are getting short.