COMPUTING DEVICE (20TH CENTURY TO COMPUTER AGE)

HARVARD MARK I

In 1937, Howard A. Aiken of Harvard University, using the techniques already developed for punched card machinery, began work on the design of a fully automatic machine in collaboration with International Business Machines Corporation. His aim was to develop a machine that could help him in the solution of difficult differential equations, the large calculation of which would have been unreal manually.

COMPONENTS

The Mark I was originally controlled from pre – punched paper tape without provision for reversal, so that automatic transfer of control instructions could not be programmed. Output was by card punch and electric typewriter.

USES

Harvard Mark I, handled 23 – decimal – place numbers (words) and could perform all four arithmetic operations; moreover, it had special built – in programs or sub routine to handle logarithms and trigonometric functions.

ENIAC

ENIAC used a word of 10 decimal digits instead of binary ones like previous automated calculator or computer. The innovation of very high speed vacuum tube switching devices led to the first all electronic computers, the Electronic Numerical Integrator And Calculator (ENIAC).

COMPONENTS

ENIAC also was the first machine to use more than 2,000 vacuum tubes, using nearly 18,000 vacuum tubes. Storage of all those vacuum tubes and the machinery required to keep the cool up 167 square metres (1,800 square feet) of floor space.

USES

In one hour ENIAC could achieve calculations that would have taken MARK I one week to perform. Addition of two numbers was in 200 microseconds while multiplication was 2,800 microseconds.

EDVAC (Electronic Discrete Variable Automatic Machine)

Mauchly and Eckert started working on it two years before ENIAC even went into operation. Their idea was to have the program for the computer stored inside the computer. This is done through the use of mercury delay line which is another way of storing 0s and 1s. EDVAC was to use binary rather than decimal number, thus simplifying the construction of the arithmetic units.

COMPONENT

  Magnetic tape reader – recorder, control unit with an oscilloscope, a dispatcher unit to receive instructions from control unit and memory, a computational unit to perform arithmetic operations, a  timer a dual memory unit and three temporary tanks holding a single word. It has 6,000 vacuum tubes, 12,000 diodes and consumed 56kW of power.

USES

 EDVAC’s addition time was 864 microseconds while multiplication is 2,900 microseconds.

UNIVAC I (Universal Automatic Computer)

The first model was built by the Eckert – Mauchly Computer Corporate, which was purchased by Remington Rand shortly before the UNIVAC went on sale. The UNIVAC I was the first computer to be widely used for commercial purpose. It was about a one – car garage.

COMPONENTS

It was 25feet by 50 feet in length, contained 5,600 tubes, 1,800 crystal diodes, and 300 relays. It utilized serial circuitry, 2.25 MHz bit rate, internal storage capacity, 1,000 words or 12,000 characters. Power consumption was about 120Kva.

USES

It was used for general purpose computing with large amounts of input and output.

DESKTOP PERSONAL COMPUTER

Desktop personal computers (PCs) are small, relatively inexpensive computer that are designed for individual users. Typically, these devices include a monitor, keyboard, mouse, and other peripherals. Desktop personal computer uses a microprocessor technology that enables manufacturers to place an entire central processing unit (CPU) on a single chip.

USES

A desktop computer is a personal computer in a form intended for regular use at a single location as opposed to a mobile laptop or portable computer.

LAPTOP AND NOTEBOOK COMPUTER

Notebook and laptop computers are portable computers that usually feature integral keyboards and monitors.

There are two basic types;

(i)                 Personal computer which run Microsoft windows like Window XP, Vista, Window 7 or 8.

(ii)               Macintosh which run versions of Mac OS, like Apple OS, Linux, UNIX etc.

ADVANTAGES

I.                    Portability: is usually the first feature mentioned in any comparison of laptops versus desktop.

II.                 Productivity: Using a laptop in place where a desktop.

III.               Immediacy: Carrying laptop means having instant access to various information, personal and work files.

IV.              Connectivity: Laptop can have easy internet and local network connectivity while remaining mobile.

Other advantages include size, low power consumption, quiet battery and all – in – one.