Based on shape Computer are Four type.
1. Microcomputers (personal computers).
2 2. Minicomputers (mid-range computers).
3. Mainframe computers.
4. Supercomputers
A.
A microcomputer is a small, relatively inexpensive computer with a
microprocessor as its central processing unit (CPU).
B.
It includes a microprocessor, memory and
minimal input/output (I/O) circuitry mounted on a single printed circuit board
(PCB).
C.
Microcomputers became popular in the
1970s and 1980s with the advent of increasingly powerful microprocessors.
These computers include:
Desktop computers – A case put under or on a desk. The
display may be optional, depending on use. The case size may vary, depending on
the required expansion slots. Very small computers of this kind may be
integrated into the monitor.
Rackmount computers – The cases of these computers fit into
19-inch racks, and maybe space-optimized and very flat. A dedicated display,
keyboard, and mouse may not exist, but a KVM switch or built-in remote control
(via LAN or other means) can be used to gain console access.
In-car computers
(carputers) – Built
into automobiles, for entertainment, navigation, etc.
Laptops and notebook
computers – Portable
and all in one case.
Tablet computer – Like laptops, but with a touch-screen,
entirely replacing the physical keyboard.
Smartphones, smartbooks, and palmtop computers –
Small handheld personal computers with limited hardware specifications.
Programmable calculator– Like small handhelds, but specialized
in mathematical work.
Video game consoles – Fixed computers built specifically for
entertainment purposes.
Handheld game consoles – The same as game consoles, but small
and portable
2. 2. Minicomputers (mid-range computers)
It is smaller in size than a mainframe computer.
·
It
is less expensive than a super and mainframe computer.
·
It
is not much more powerful than the mainframe and supercomputer, but powerful
than microcomputers.
·
It
supports multiprocessing and multi-tasking.
·
The
term "minicomputer" developed in the 1960s to describe the smaller computers that became
possible with the use of transistors and core memory technologies, minimal
instructions sets and less expensive peripherals such as the ubiquitous
Teletype Model 33 ASR. They usually took up one or a few 19-inch rack cabinets,
compared with the large mainframes that could fill a room.
· In terms of relative computing power
compared to contemporary mainframes, small systems that were similar to
minicomputers had been available from the 1950s. In particular, there was an
entire class of drum machines, like the UNIVAC 1101 and LGP-30, that share some
features of the minicomputer class. Similar models using magnetic delay line
memory followed in the early 1960s. These machines however, were essentially
designed as small mainframes, using a custom chassis and often supporting only
peripherals from the same company.
3. Mainframe computers
A
mainframe computer is large but not
as large as a supercomputer and has more processing power than some other
classes of computers, such as minicomputers, servers, workstations, and
personal computers. Most large-scale computer-system architectures were
established in the 1960s, but they continue to evolve. Mainframe computers are
often used as servers.
The
term mainframe was derived from the large cabinet, called a main frame that
housed the central processing unit and main memory of early computers. Later,
the term mainframe was used to distinguish high-end commercial computers from
less powerful machines.
Super Computer
44. Supercomputers
A
supercomputer is a computer with a high
level of performance as compared to a general-purpose computer. The
performance of a supercomputer is commonly measured in floating-point
operations per second (FLOPS) instead of million instructions per second
(MIPS). Since 2017, there are supercomputers which can perform over 1017 FLOPS
(a hundred quadrillion FLOPS, 100 petaFLOPS or 100 PFLOPS).
For
comparison, a desktop computer has performance in the range of hundreds of
gigaFLOPS to tens of teraflops. Supercomputers
were introduced in the 1960s, and for several decades the fastest were made by
Seymour Cray at Control Data Corporation (CDC), Cray Research and subsequent
companies bearing his name or monogram. The first such machines were highly
tuned conventional designs that ran more quickly than their more
general-purpose contemporaries. Through the decade, increasing amounts of
parallelism were added, with one to four processors being typical. In the
1970s, vector processors operating on large arrays of data came to dominate.
A
notable example is the highly successful Cray-1
of 1976. Vector computers
remained the dominant design into the 1990s.
Article Source: https://en.wikipedia.org/wiki/Classes_of_computers
