Minicomputer

Shopping on line can be easy, simple and save you lots of money. It can also take a lot of your time, frustrate you, and result in unwanted purchases. Now the same can be said for regular high street shopping, but with the vast opportunity presented by the Internet it will pay you to spend a few minutes reading this and understanding how to better optimize your Minicomputer shopping experience:

1. Compare - without doubt the biggest advantage that the Minicomputer offers shoppers today is the ability to compare thousands of Minicomputer at a time. This is a great thing, but not necessarily all the time! Too much can be daunting at times so take advantage of the great comparison sites and where possible let them do the hard work for you.

2. Research - if it has been said it will be on the internet. Ignorance is no longer a justifiable reason for buying the wrong thing. Take the time to research in detail everything that you could possible want to know about

3. Testimonials - don't know anybody that has bought a Minicomputer? Wrong! If the Minicomputer is good the internet will let you know. Use the Internet as a friend and get testimonials before you buy.

4. Questions - Got a question about Minicomputer then search the Forums, FAQ's, Blogs etc. Don't be afraid to ask .....

5. Reputation - Never heard of the company selling Minicomputer? Don't worry, no reason why you should know every company in the world, but you know someone that does! Use the internet to find out what people are saying about Minicomputer and build up a picture of their reputation for sales, returns, customer service, delivery etc.

6. Returns - still worried that even after all of the above your Minicomputer wont be what you want? Check out the returns policy. There is so much competition now that someone, somewhere is bound to offer the terms that you are comfortable with.

7. Feedback - happy with your Minicomputer then let people know, after all you are depending on others people input in your buying decision, so why not give a little back.

8. Security - check for the yellow padlock on the Minicomputer site before you buy, and the s after http:/ /i.e. https:// = a secure site

9. Contact - got a question about Minicomputer, or want to leave a comment then check out the sites contact page. Reputable companies have them and respond.

10. Payment - ready to pay for your Minicomputer, then use your credit card or PayPal! Be aware of companies that don't accept them, there may be genuine reasons but given the huge amount of choice you have when buying online there is no reason at all not to buy via credit card or PayPal.

Minicomputer (colloquially, mini) is a largely obsolete term for a class of multi-user computers that lies in the middle range of the computing spectrum, in between the largest multi-user systems (mainframe computers) and the smallest single-user systems (microcomputers or personal computers). Formerly this class formed a distinct group with its own hardware and operating systems. While the distinction between mainframe computers and smaller computers remains fairly clear, contemporary middle-range computers are not well differentiated from personal computers, being typically just a more powerful but still compatible version of personal computer. More modern terms for minicomputer-type machines include IBM midrange computer (IBM parlance), computer workstations (Sun Microsystems and general Unix/Linux parlance), and Server (computing)s.

History 1960s: Origin; 1970s: Market entrenchment The term “minicomputer” evolved in the 1960s to describe the “small” third generation computers that became possible with the use of transistor and core memory technologies. The term came in fashion about the same time as the miniskirt and mini cars. They usually took up one or a few cabinets the size of a large refrigerator or two, compared with mainframe computer that would usually fill a room. The first successful minicomputer was Digital Equipment Corporation’s 12-bit PDP-8, which cost from United States dollar16,000 upwards when launched in 1964. The important precursors of the PDP-8 include the PDP-5, LINC, the TX-0, the TX-2, and the PDP-1. Digital Equipment gave rise to a number of minicomputer companies along Massachusetts Route 128, including Data General, Wang Laboratories, Apollo Computer, and Prime Computer.

The 7400 series of transistor-transistor logic integrated circuits started appearing in minicomputers in the late 1960s. The 74181 arithmetic-logic unit (ALU) was commonly used in the central processing unit data paths. Each 74181 had a bus width of four bits, hence the popularity of bit-slice architecture. The 7400 series offered data-selectors, multiplexers, three-state buffers, memories, etc. in dual in-line packages with one-tenth inch spacing, making major system components and architecture evident to the naked eye. (Starting in the 1980s, many minicomputers used VLSI circuits (Very Large Scale Integration), often making the hardware organization much less apparent.)

As microcomputers developed in the 1970s and 1980s, minicomputers filled the mid-range area between low powered microcomputers and high capacity mainframes. At the time microcomputers were single-user, relatively simple machines running simple program-launcher operating systems like CPM operating system or MS-DOS, while minis were much more powerful systems that ran full multi-user, multitasking operating systems like OpenVMS and Unix, often with time-sharing versions of BASIC for application development (MAI Basic Four systems being very popular in that regard). The classical mini was a 16-bit computer, while the emerging higher performance 32-bit minis were often referred to as superminis.

Mid-1980s, 1990s: The minis give way to the micros The decline of the minis happened due to the lower cost of microprocessor based computer hardware, the emergence of inexpensive and easily deployable local area network systems, the emergence of the 80286 and the 80386 microprocessors, and the desire of end-users to be less reliant on inflexible minicomputer manufacturers and IT departments/“data centers”—with the result that minicomputers and dumb terminals were replaced by networked workstations and server (computing)s and IBM PC compatibles in the latter half of the 1980s.

During the 1990s the change from minicomputers to inexpensive PC networks was cemented by the development of several versions of Unix to run on the Intel x86 microprocessor computer architecture, including Solaris (operating system), FreeBSD, NetBSD and OpenBSD. Also, the Microsoft Windows series of operating systems, beginning with Windows NT, now includes server versions that support preemptive multitasking and other features required for servers.

As microprocessors have become more powerful, central processing unit built up from multiple components—once the distinguishing feature differentiating mainframes and midrange systems from microcomputers—have become increasingly obsolete, even in the largest mainframe computers.

Digital Equipment Corporation was the leading minicomputer manufacturer, at one time the 2nd largest computer company after IBM. But as the minicomputer declined in the face of generic UNIX servers and Intel based PCs, not only DEC, but almost every other minicomputer company including Data General, Prime Computer, Computervision, Honeywell and Wang Computer, many based in New England also collapsed. DEC was sold to Compaq in 1998.

The minicomputer’s industrial impact and heritage Several pioneering computer companies first built minicomputers, such as Digital, Data General, and Hewlett-Packard (who now refers to its HP3000 minicomputers as “servers” rather than “minicomputers”). And although today’s PCs and servers are clearly microcomputers physically, architecturally their CPUs and operating systems have evolved largely by integrating features from minicomputers.

In the software context, the relatively simple OSes for early microcomputers were usually inspired by minicomputer OSes (such as CP/M's similarity to Digital's RSTS-11) and multiuser OSs of today are often either inspired by or directly descended from minicomputer OSs (UNIX was originally a minicomputer OS)

List of some notable minicomputers

Control Data’s CDC 160A and CDC 1700
Digital Equipment Corporation Programmed Data Processor and VAX series
Data General Data General Nova
Hewlett-Packard HP3000 series
Honeywell-Groupe Bull Level 6/DPS 6/DPS 6000 series
IBM IBM midrange computers
Norsk Data Nord-1, Nord-10, and Nord-100
Prime Computer Prime 50 series
Scientific Data Systems SDS-92
Wang Laboratories 2200 and VS series