Roots of Smartphone OS
OS is the acronym for operating system. There are two main camps of Smartphone OS: Android and iOS. Other smartphone OS are negligible. However, most of us do not realise that the roots of both OS are Unix, which has existed since 1970.
Development Of Unix
Unix was originally written for mini computers a.k.a. small main frame computers, cf. microcomputers a.k.a. PC or personal computers. Each minicomputer allows 10 or 20 non-processing terminals for simultaneous users. Each terminal typically consists of a keyboard and a text-based monitor without graphical capability.
Unix was originally developed as a secure multitasking and multi-user (on time-sharing basis) OS with command line interface. Unix has been designed from ground up placing priority on security. This is unlike Microsoft DOS and Windows, which is a single-user OS until the Server version of Windows has been released. The Author considers Windows as the most insecure major OS.
Variances Of Unix
There are many variances of Unix:
* IBM has AIX,
* HP has HP UX,
* Sun Microsystems (acquired by Oracle) has Solaris, and
* Digital Equipment Corporation, also known as DEC, has OpenVMS.
DEC had been the leading vendor for minicomputers and was acquired by Compaq, who later merged with HP. DEC also held the glory of producing the first 64-bit, the fastest and the most advanced microprocessor called Alpha in 1992. AMD released its first 64-bit x86 microprocessor in 2003 and Intel in 2004. Another decade lapsed when Apple released the first 64-bit ARM microprocessor called A7 for smartphones in 2013.
Both Alpha, ARM and many other advanced microprocessors have RISC (Reduced Instruction Set Computing) architecture. The architecture of Intel and AMD x86 microprocessors remains as CISC (Complex Instruction Set Computing), which is older, in order to maintain compatibility with old computer platform.
macOS And iOS
The Beginning Of PC Era
Steve Jobs and Steve Wozniak founded Apple Inc. in 1976. The initial primitive Apple OS with command line interface was originally written by Steve Wozniak. The OS could run BASIC (a programming language) source code programmes in translation mode.
IBM developed PC in 1980 and decided to contract the OS for PC to Microsoft, and this led to MS DOS, again having command line interface. Microsoft convinced IBM for Microsoft to retain the right to license MS DOS to other vendors and users. Computers (IBM compatible) from other vendors and MS DOS flourished. Microsoft became the largest technology company of that era.
The Origin Of Graphical User Interface
In 1979 Steve Jobs visited Xerox PARC and saw the first GUI (graphical user interface) computer Xerox Alto. Steve was immediately convinced. Apple licensed the concept from Xerox, developed and Launched Apple Lisa in 1983, and then Apple Macintosh with Mac OS 1.0 in 1984. It was the first popular OS with GUI and turned a new leaf in the history of OS. Apple Macintosh were popular especially in desktop publishing, graphical design and CAD.
Steve Jobs had a power struggle with Apple’s CEO, John Scully, whom Steve had employed. In 1985, Steve Jobs resigned from Apple. Later in that year he founded NeXT Inc.
The Rise Of Microsoft Windows
Microsoft developed Windows 1.0, a GUI running on top of MS DOS and released it in late 1985. Windows was never popular until Release 3.0 arrived in 1990. 1995 was the beginning of downtrend for Apple when Windows 95 arrived and finally became 32-bit OS. Earlier versions of DOS had been 8-bit and 16-bit. Sales of Apple computers dropped because now Windows proclaimed some of the technology of Macintosh OS though the latter was considered superior. At the same time IBM also had developed and released OS/2 for PC, which never became popular. Later, Microsoft upgraded Windows 7 to 64-bit.
NeXTStep
NeXT Inc. developed and started selling NeXT computer in 1989 with NeXTStep, an OOP (object oriented programming) and Unix compliant OS. NeXTStep was considered ahead of its time. The OS has incorporated a dictionary in it and users can right-click any word to check with the dictionary. OOP is now common programming practice.
Reinventing Mac OS
In 1993, NeXT withdrew from hardware business and concentrated on NeXTStep. Apple acquired NeXT for its OS technology in 1997 and brought Steve Jobs backed. Later in the same year Steve became Interim CEO. Apple was saved from bankruptcy. The term “Interim” was eventually dropped. Apple adopted and rewrote NeXTStep to become Mac OS X 10.0 for Macintosh and replaced Mac OS 9 in 2001, while maintaining backward compatibility with existing software applications. Letter “X” here means NeXTStep, or UniX compliant, signifying the birth of a new OS for Macintosh.
Porting Mac OS To x86 Platofrm
Apple had been making Macintosh computers for PowerPC line of processors, which had RISC Architecture. However, Apple had planned to switch from PowerPC processors to Intel x86 processors because Intel’s R&D was very much faster due to Intel’s financial strength. Intel had been the largest processor manufacturer. Apple planned Mac OS X 10.4 for both processor platforms and released it first on PowerPC platform in April 2005, then version 10.4.4 also on Intel x86 platform in Jan 2006. The version on Intel x86 platform incorporated Rosseta, a translation process for running software applications written for PowerPC.
In Oct 2007, Apple released Mac OS X 10.5 Leopard as a Universal Binary (fat binaries), i.e. incorporating both binaries, one for PowerPC platform and another for Intel x86 platform. Binaries refer to compiled computer programmes in the form of machine codes (executables), allowing processors to execute. This form is not directly comprehensible by human. The opposite are source codes, which are uncompiled original computer programme, and can easily be read and understood by programmers.
iOS
In 2005, Steve planned to produce iPhone. Apple shrunk and rewrote OS X to become iOS in 2007. The dictionary available in iOS is inherited from NeXTStep through OS X. It can be activated by highlighting any word, then clicking the right command.
Linux And Android
The Advent Of Linux
The most important variance of Unix today is Linux. The defining component of Linux is the Linux kernel, first released in 1991 by Linus Torvalds when he was a student of University of Helsinki, Finland.
Linux is developed as a free and open source-code operating system, originally for personal computers of Intel x86 platform. Linux has since been ported to more computer platforms than any other operating system. Almost all vendors originally producing mainframes, minicomputers and workstations for various variances of Unix now adopt Linux. In other words, Linux is the de facto standard for Unix now.
The Rise Of Android
Android Inc. was a startup company in 2003 to develop Android as an OS for mobile phones, to rival Symbian and Windows Mobile at that time. The programmers did not start from scratch but instead adopted Linux kernel to develop and built Android GUI on top. Google acquired the company in 2005. This is perhaps the best ever Google’s acquisition. In 2007, Google was about to release Android when Apple released iPhones and iOS. Seeing that iOS was far superior, Google held back and rewrote the GUI of Android according to the concept of iOS.
Dominance of Linux
Because of the dominance of Android on smartphones, Linux has the largest installed base of all general-purpose operating systems. Linux, in its original form, is also the overwhelmingly leading operating system for servers, and is used on virtually all mainframes and all supercomputers. However, it is used on about 1.6% of PC only, due to historical dominance of Windows and software on Windows platform.
Chrome OS, an OS with Linux Kernel produced by Google, acclaims about another 5% of all notebooks and nearly 20% of the sub-$300 notebook sales.
De facto OS For Embedded System
Linux and Android also run on most embedded systems, which are devices with built-in operating system, a.k.a firmware. This includes many devices such as TV, set-top boxes, GPS and etc. In the coming era of Internet of things, the author believes all these little “things” or devices connected to Internet will be using low-cost low-energy-consumption ARM chips running free and simplified Linux, Android or derivatives. The exceptions will be a small fraction of iOS (or derivatives) devices. Please also refer to the following for Internet of things:
https://en.m.wikipedia.org/wiki/Internet_of_things
Only Two Main Camps Of OS
Numerous OS had been developed since the first release of Unix. Despite this, presently almost all non-Windows are Unix-based OS. Almost all non-Unix are Windows. Linux and Android will remain the most influential and the most established OS in future, at least for many decades.