The Operating System: the soul of PCs

(To Carlo Mauceli)
05/07/21

We can affirm that the first great IT revolution took place with the birth of Operating Systems which in fact allowed the whole world to use devices.

Thanks to faster and increasingly "cheaper" technologies, computers have had an exponential development and Bill Gates' dream, that is to have a computer on every desk, has come true. Not only; we have gone far beyond that nowadays, compared to the past, there is a great variety of processing systems available and there is no longer a need for a desk but our pockets are enough.

Let's see, therefore, how operating systems were born and, really, what they are.

To keep things simple, an operating system is software that is loaded when the computer starts up and allows other software to be used. We can say that, by far, it is the most used software in the life of a computer and it is the means through which the computer itself lives. Without the operating system, many operations could not exist.

We can divide the operating system into two large classes:

  • The first is the textual one;
  • The second is the graphic one. In fact, the most used.

If we go back in time, we can date the progenitor of the operating system between 1945 and 1955 when the first electronic computers equipped with thermionic valves appeared. These were very expensive machines in which the programs were written in machine language and inserted into the programmer through punch card readers and the results of which were subsequently sent to the printer.

In the decade from 1955 to 1965, the first reliable processors appeared, the so-called Mainframes, thanks to the invention of transistors that replaced thermionic tubes. They were always hyper-expensive and gigantic machines whose buyers were only banks, universities and computing centers. At the same time the first real programming language was born, Fortran, which allows for an ever-increasing number of programmers.

And here, finally, we come to the first real Operating System, produced by General Motors for their IBM 701. Since direct memory access (DMA) technology had not yet been introduced, all input / output operations were charged. of the CPU which slowed down the actual execution terribly. For this reason, the batch solution was adopted, the so-called batches, whereby the I / O is managed by a cheaper computer such as the IBM 1401 and the processing entrusted to a central computer such as the IBM 7094. The system operating of these computers, the so-called Batch Monitor, performed few services such as the management of the Input / Output and the interpretation and execution of the commands contained in the control cards.

In the early 60s, with the ever increasing development of transistors, there were the first operating systems in time-sharing multiprogramming and real-time systems for process control. In 1962 at MIT the CTSS was created, the first time-sharing system, on an IBM 7094 and it was in this period that MIT, General Electric and Bell Labs jointly developed MULTICS, an operating system capable of supporting hundreds of users in time-sharing, a sort of milestone that influenced the development of the operating systems that would arrive later.

The spring of 1964 saw the birth of IBM OS / 360, an all-encompassing operating system capable of managing batch, time-sharing and real-time, supporting both scientific computing, with the Fortran language, and commercial, with the Cobol management language, created the following year.

In the years immediately following, with the development of mini-computers, special operating systems were developed, the most famous of which is UNIX.

With the advent of UNIX, which took place in 1969, we enter a new era that sees the birth of heterogeneous operating systems:

  • OS / 370 from IBM introducing the concept of virtual machine;
  • VM / CMS, born in 1972;
  • Operating systems distributed over a network of processors.

These operating systems offer, for the first time, functions that were previously characteristic of application programs, leading to the birth of multiprocessor computers.

We cannot at this point not dedicate a moment to UNIX. This system was designed starting in 1969 by a group of AT&T researchers at Bell Labs including Ken Thompson who also worked on the Multics project and Dennis Ritchie, one of the pioneers of modern computing, important for having been the 'inventor of the C language.

The birth of UNIX gave rise to a series of variants such as BSD (Berkley Software Distribution), SCO System V, Minix and, subsequently, LINUX (which was born as a kernel) made by Linus Torvalds.

At the turn of the 70s / 80s we witness the phenomenon of the reduction of hardware costs thanks to the development of LSI (Large Scale Integration) technology and the construction of integrated chips and the birth of Personal Computers capable of having performance similar to those of average computers. - large than 10 or 20 years ago. At the same time, in 1964, Basic was born, a new programming language.

The most important operating systems of this period are:

  • CP / M-80 from Digital Research for Intel 8080 and Z-80 CPUs;
  • Microsoft MS-DOS, similar to the CP / M-8 adopted by IBM for its Personal Computer, launched in 1981 and which laid the foundations for the development of Microsoft.

These years are extremely lively and fertile from an IT point of view and Italy also benefits from this with the affirmation and subsequent rapid growth of Olivetti which in 1972 constitutes the Software Development Service in Ivrea, which can count on the experience gained by some engineers. in the USA at MIT. It is from this group, released from the product development groups to respond to a relaunch strategy decided by the top management of the time, the CEO Ottorino Beltrami and the head of product planning Marisa Bellisario, that between 1973 and 1975 the Cosmos was born. , operating system of the TC 800.

The TC 800 is a video-keyboard banking terminal system, each of which has sufficient memory and disk to process the local portion of the counter banking transaction. The terminals are then connected to the master, always from the same family, which concentrates everything by communicating with the central computer (usually a large IBM). The importance of innovation lies in the fact that all processing no longer takes place in the center, but partly takes place at the counter terminals, which become an active part of a complex system.

The avant-garde position in this field was confirmed at the beginning of the 80s with Cosmos II, on S1000 minicomputers, a system that features ISO and ECMA standard LAN and WAN protocols, international standardization bodies in which Olivetti plays an important role.

The skills acquired in the software subsequently allowed Olivetti to have an important role also in large Italian programs (Project aimed at Informatics of the CNR), and in Europe (Esprit Project of the European Union).

Starting from 1984, the operating systems with graphic interface explode. Inspired by the graphical interface developed by Xerox a few years earlier, Apple gives life, on the Macintosh, to Mac OS which represents the first PC operating system with graphical interface that represented a real revolution.

Soon after we witness the birth of the X Windows System in UNIX and Windows by Microsoft which, at the beginning, was not a real operating system but an extension of MS-DOS.

In 1987 IBM developed OS / 2 for its PS / 2 PC which was not, however, a great success. The imposition on the market by Microsoft takes place with the birth of Windows 3.0 in 1990, an operating system that supports multitasking and virtual memory, which will be followed by Windows 3.10 and 3.11 while in 1992 multimedia support and network functions are introduced. for lan and peer to peer.

Only starting with Windows 95 can we speak of a real operating system for Windows in addition to the fact that we pass from 16-bit to 32-bit computing. Then follow Windows 98, in 1998, Windows ME, in 2000, Windows 2000, also in 2000, Windows XP, in 2001 and gradually all the others up to nowadays Windows 10.

Linux in its various distributions also provides the graphical interface: Red Hat, in 1994, Debian GNU / Linux, in 1996, Ubuntu in 2005.

A separate mention deserves the network operating systems that were born with the phenomenon that developed in the 80s with the birth of computer networks.

They were born like this:

  • Network Operating Systems which are normal operating systems with the addition of software for connection to remote machines and therefore to their shared resources such as files and printers;
  • Distributed Operating Systems which are operating systems that run on multi-processor systems or that send processes to be processed to other computers on the network.

On this basis, Novell's Netware operating system was born in 1983, which allows the network connection of computers equipped with operating systems such as MS-DOS, Windows, Unix and Mac OS.

In the wake of the new needs for connection and sharing of information and devices, Microsoft develops various network operating systems, always called Windows: NT, in 1993, 200 Server, in 2000, Server 2003, in 2003, Server 2008, in 2008, Server 2012, in 2012, etc.

Nowadays, compared to the past, a great variety of processing systems of the most disparate dimensions and performances are available at low costs and interconnections between the various devices in both wired and wireless modes are increasingly widespread.

All this has led to the development of operating systems for the most varied architectures and in particular for mobile phones whose two most important operating systems are Apple's IOS and Google's Android.

But we will talk about this in a future article ...

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Images: web