Classification of computers according to size and latest versions of operating systems of computers.

Mainframe Computers

                    Well, these are very huge computers. It is interesting how the word ‘mainframe’ came into use. In fact, because the different units of computer were installed in a frame, it started to be called a computer in main frame and today a class of computers are called Mainframe computers.Mainframe computers are very powerful computers with large memory and processing capabilities. It can support hundreds of users simultaneously.

Mini Computers 

               Mini computers are medium sized computers – much larger than the personal computers we are using and smaller compared to the mainframe computers. These computers can support multiple users simultaneously and is less powerful than mainframe computers. A Minicomputer was typically a stand alone device that was ideal for use by small and mid-sized businesses who needed more power and memory than could be obtained with microcomputers, but did not have a need for the resources provided by mainframes. More recently, a minicomputer is thought of in terms of being a server that is part of a larger network.

 

Micro Computers

                 A class of computers that use microprocessor as their central processing unit and are the smallest of the types are the micro computers. Microcomputers are often called personal computers (PCs) because they are intended to be used by a single person at a time. While mainframe and mini computers can support multiple users simultaneously, it can support only one user at a time.

Micro computers can further be classified into desktop computers (that can fit within the top of a desk), laptops (portable computers that can be operated on your lap) and palmtops (hand held computers).

Super Computers  

               Super Computers are the fastest type of computer. Supercomputers are very expensive and are employed for specialized applications that require immense amounts of mathematical calculations. For example, weather forecasting requires a supercomputer. Other uses of supercomputers include animated graphics, fluid dynamic calculations, nuclear energy research, and petroleum exploration.The chief difference between a supercomputer and a mainframe is that a supercomputer channels all its power into executing a few programs as fast as possible, whereas a mainframe uses its power to execute many programs concurrently.

 

Latest version of operating system

• Acorn Computers
• ARX
• Arthur
• RISC OS
• MOS
• Panos
• RISC iX

Amiga Inc.

•    AmigaOS 
•    AmigaOS 1.0-3.9 (Motorola 68000)
•    AmigaOS 4 (PowerPC)
•    Amiga Unix (aka Amix)

Apple Inc.

•    Apple DOS
•    UCSD Pascal
•    ProDOS
•    GS/OS

 

IBM

• BOS/360 (Basic Operating System)
• MTS (Michigan Terminal System for IBM System/360)
• RTOS/360 (IBM's Real Time Operating System, ran on 5 NASA custom System/360-75s)
• TOS/360 (Tape Operating System)
• TSS/360 (IBM's Time Sharing System)
• MUSIC/SP (developed by McGill University for IBM System/370)
• ORVYL and WYLBUR (developed by Stanford University for IBM System/360)

Hewlett-Packard

•   HP Multi-Programming Executive; (MPE, MPE/XL, and MPE/iX) runs on HP 3000 and HP e3000 mini-computers.
•   HP-UX; runs on HP9000 and Itanium servers - from small to mainframe-class computers.

Honeywell

•    Multics 
•    GCOS

Intel Corporation

•  iRMX; real-time operating system originally created to support the Intel 8080 and 8086 processor families in embedded applications.
•   ISIS-II; "Intel Systems Implementation Supervisor" was THE environment for development of software within the Intel microprocessor family in the early 1980s on their Intellec Microcomputer Development System and clones. ISIS-II worked with 8 inch floppy disks and had an editor, cross-assemblers, a linker, an object locator, debugger, compilers for PLM (PL/I for microprocessors of the 8080/86 family), a BASIC interpreter, etc. and allowed file management through a console.

Microsoft

 

• Windows Vista (Windows NT 6.0) January 31, 2007
• Windows Azure (based on Windows Vista) 2009
• 
• Windows Home Server (based on Windows Server 2003) February 28, 2008
• Windows Server 2008 (based on Windows Vista) February 28, 2008
• Windows 7 (Windows NT 6.1) October 22, 2009 
• Windows Server 2008 R2 (based on Windows 7) October 22, 2009
• Windows Home Server 2011 (based on Windows Server 2008 R2) April 6, 2011
• Windows 8 Consumer Preview (First downloadable release) March 1, 2012
• Windows 8 Server Beta (First downloadable release) March 15, 2012
• Windows CE (OS for handhelds, embedded devices, and real-time applications that is similar to other versions of Windows) May 30, 2002
• Windows CE 3.0 December 25, 2002
• Windows CE 5.0 February 27, 2004
• Windows CE 6.0 May 5, 2004 
• Windows Mobile (based on Windows CE, but for a smaller form factor) April 14, 2005 
• Windows Phone October 21, 2010
• Singularity - A research operating system written mostly in managed code (C#) November 30, 2009 
• Midori - A managed code operating system July 21, 2010