How Computers Store Data

TERMS discrete data continuous data, bi-stable device, number system, binary number system, denary number system human-readable data machine –readable data natural numbers whole numbers, integers real numbers, magnitude base, number, digit

QUIZ Classify each set of data as discrete or continuous. 1) The number of suitcases lost by an airline. 2) The height of corn plants. 3) The number of ears of corn produced. 4) The number of green M&M's in a bag. 5) The time it takes for a car battery to die. 6) The production of tomatoes by weight.

QUIZ ANSWERS 1) Discrete. The number of suitcases lost must be a whole number. 2) Continuous. The height of corn plants can take on infinitely many values (any decimal is possible). 3) Discrete. The number of ears of corn must be a whole number. 4) Discrete. The number of green M&M's must be a whole number. 5) Continuous. The amount of time can take on infinitely many values (any decimal is possible). 6) Continuous. The weight of the tomatoes can take on infinitely many values (any decimal is possible).

Why do computers store data? For processing Temporarily using Random Access Memory (RAM) For later use permanently or semi-permanently using secondary storage devices and media Computers do not store data the way we see it, but in the form of binary digits

Why binary digits? The computer is an electronic device The computer is a digital device Electronic the computer uses electricity to work Digital the use of binary digits to store data

The computer’s memory The computer’s memory is made up of tiny two-state electronic devices called bi-stable devices. A bi-stable device can exist in only one of two possible states i.e. on or off. Bi-stable devices respond to the presence or absence of an electric current: Absence of an electric current - off state Presence of an electric current - on state

Binary digits and data Binary digITS (BITS) 1  ON 0  OFF This is why data is stored in the form of binary digits (bits) Input data is converted to binary digits in order to be processed and stored  

Binary digits and data (cont’d) Information for the user is converted from binary digits into human-readable form   Every character on the keyboard can be represented internally using a combination of 8 bits or 1 byte The computer uses various representation schemes to convert data to binary form

Numeration/number system: any notation for the representation of numbers human-readable format is a representation of data or information that can be naturally read by humans Machine readable format-

Homework Logon to IT for CSEC Read and take notes on pages 55 – 56

Homework (cont’d) All ___________ that is _________ into a computer system must be _________ temporarily in ________________. The computer’s ___________ is made up of ___________________ which can exist in only one of _______ possible __________. As a result, the _________________ one and zero are used to represent the ________ and __________ states respectively. ___________ data is therefore _____________ to its binary __________________ in order to be _______________ and ____________. It is then _____________ from ______________ back to its original form in order to be ___________ to the user. Fill in the blanks in the above paragraph using the words given in the list below. Remember that a word may be used more than once. Main memory, data, representation, memory, stored, bistable devices, converted, states, output, two, binary digits, input, on, processed, off, binary.