IPT 2009

End of Year Exam Study Guide

How to use this study guide

• This guide needs to be used with the course text, notes from class and the internet

• Each bullet point needs:– to be researched fully– Written notes (no cutting and pasting)– Include images – Definition– Example of its use

Information systems in context diagrams

• the environment – everything that influences and is influenced by the information system

• the purpose – a statement identifying who the information system is for and what it needs to achieve

• the information system – a set of information processes requiring participants, data/information and information technology built to satisfy a purpose

• information processes – computer based and non-computer based activities• information technology – hardware and software used in information

processes• data – the raw material used by information processes• information – the output displayed by an information system• user – a person who views or uses the information output from an

information system• participant – a special class of user who carries out the information

processes within an information system

Information processes

• Collecting – the process by which data is entered into or captured by a computer system, including:

• deciding what data is required• how it is sourced• how it is encoded for entry into the system• Organising – the process by which data is structured into a form appropriate for the

use of other information processes such as the format in which data will be represented

• Analysing – the process by which data is interpreted, transforming it into information

• Storing and Retrieving – the process by which data and information is saved and accessed later

• Processing – a procedure that manipulates data and information• Transmitting and Receiving – the process that sends and receives data and

information within and beyond information systems• Displaying – the process that controls the format of information presented to the

participant or user

Barcode scanners

Barcodes are produced and being read. It is operate by reflecting light off the barcode image; light reflects well off white and not very well off black. This digital data may be analysed, organised and processed into numbers or text or it may remain as image data in the form of bitmaps. CCD Barcode Scanners charges coupled devices contain one or more rows of photocells built into a single microchip. There three types of scanners which is LED wand, CCD barcode scanners and multi- directional laser. The reflected light form the LED is measured using a single photocells. Lasers are high intensity beams of light and as such they can be directed very precisely.

Device driversA device driver simplifies programming by acting as a translator between a hardware device and the applications or operating systems that use it. Programmers can write the higher-level application code independently of whatever specific hardware device it will ultimately control, because code and device can interface in a standard way, regardless of the software superstructure or of underlying hardware. Every version of a device, such as a printer, requires its own hardware-specific specialized commands. In contrast, most applications utilize devices (such as a file to a printer) by means of high-level device-generic commands such as PRINTLN (print a line). The device-driver accepts these generic high-level commands and breaks them into a series of low-level device-specific commands as required by the device being driven. Furthermore, drivers can provide a level of security as they can run in kernel-mode, thereby protecting the operating system from applications running in user-mode.

Random access memory (RAM)RAM holds both the software and the data used by CPU during processing. As secondary storage is many thousands of times slower than RAM, a noticeable drop in performance will certainly result .A retrieving process that would take seconds using RAM will take hours using a typical hard disk. The speed at which data held in RAM can be accessed is important for analysing processed. Different types of RAM are able to operate at different speeds.

System clock

The system clock is located on the motherboard. The signal generated is transmitted along a wire within the control bus and hence is available to all devices connected to the system bus .The clock signal continuously alternated between high (1) and low (0) at a constant pace. The transition form high to low and in some instances also from low to high are used to synchronise the transfer of data and also the operation of all components connected to the system bus.

Data storage types• Primary Storage :

Basically, primary storage is the memory part of the computer itself. Primary storage includes the Random Access Memory (RAM) and Read Only Memory (ROM). • Secondary Storage

Hard disks, magnetic tapes and all other data storage devices are included in the secondary storage. They are external to the processor and are used to increase the storage capacity of the computer. The secondary storage is non-volatile and can retain information even after the computer is switched off.

• Tertiary Storage

Tertiary data storage is the third data storage out of the three types of data storage. The tertiary devices includes the storage devices that are connected to the computer in the form of removable mass storage devices. Tertiary storage is often used to store those files that are rarely accessed by the computer user.

Streaming dataStreaming media are multimedia that are constantly received by, and normally presented to, an end-user while being delivered by a streaming provider. Data is received into one end of the buffer and removed from the other end for decompression and subsequent display.

Display devices (LCD’s)

Digital to analog conversion (DAC)

Social and ethical issues

Vector graphics and Bitmaps

Volatile/non-volatile storage devices

Modulation

Audio processing

Sampling

File formats

Data collection devices (flatbed scanners)

Hardware (soundcard processing)

Synchronous asynchronous

Communication

Electronic mail applications

Data storage (backup)

Context diagrams

Optical character recognition (OCR)

Website layout, navigation and design

Team management