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(pictures) and menus (list of choices) that users can select with a mouse. This enables
new computer users to learn to use a PC quickly. Several new PC-based applications
were also developed to make the PCs a powerful tool. Notable among these were
powerful word processing packages that allowed easy development of documents,
spreadsheet packages that allowed easy manipulation and analysis of data organized in
columns and rows, and graphics packages that allowed easy drawing of pictures and
diagrams. Another very useful concept that became popular during the fourth-generation
period was that of multiple windows on a single terminal screen. This feature allowed
users to simultaneously see the current status of several applications in separate windows
on the same terminal screen.
In the area of software for large-scale, computers, the key technologies that became
popular during the fourth-generation include multiprocessing operating systems, and
concurrent programming languages. The multiprocessing operating systems allowed
mainframe systems to be built of multiple processors (a main processor and several
subordinate processors) in such a manner that the subordinate processors could be used to
manage the user terminals and peripheral devices, allowing the main processor to
concentrate on processing the main program. This helped in improving the overall
performance of mainframe systems by several fold. The multiprocessing operating
systems were also used with the supercomputers to extract the best performance from the
large number of processors used in these systems. Concurrent programming languages
further helped in effectively using the multiprocessing capabilities of these systems by
allowing the programmers to write their applications in such a way that parts of the
application can be executed in parallel on different processors. The most ambitious
language of this type was ADA.
During the fourth-generation period, the UNIX operating system also became very
popular for use on large-scale systems. Additionally, due to the proliferation of computer
networks, several new features were included in existing operating systems to allow...
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This document was uploaded on 04/07/2014.
- Spring '14