Information Processing

Main Topics of Study:

A. Introduction

  • Definitions of hardware, software, package, program, data, parameter.
  • Overview of the range of computers currently used from lap-top to supercomputer.
  • Configuration diagram showing how the components of a computer system are related. Difference between control signal and data flow.

B. Input

  • Review of methods of data capture to include OCR, OMR, MICR, barcodes, text/image scanners, magnetic stripe, voice, touch screen, keyboard, and concept keyboard.
  • Advantages and disadvantages of these methods of data capture when compared with others. In particular, a comparison of speeds, costs, user involvement, accuracy of the data received by the computer.
  • Choose the best data capture method for a given application.
  • Conditions required for each of these data capture devices to be used. A detailed explanation of the internal operation is not required.

C. Data checking

  • Difference between validation and verification.
  • Validation checks – range, data type, presence, sequence.
  • Specifying the validation possible for a given set of data.
  • Check digit systems – normally using modulo-11 and weights 6,5,4,3,2,1 etc.
    • Specify which data can/should contain check digits.
    • State the guarantees that check digit numbers provide.
    • Calculate the check digit for a given number.
    • Validate a number which contains a check digit.
    • The use of “X” as a check digit.

D. Output

  • Ways in which data can be represented – tables, lists, summary statistics, charts, textual reports.
  • Name the range of printers currently available – laser, ink jet.
  • Advantages and disadvantages of different types of printers.
  • Screen output. Its limitations.
  • Identifying whether screen or printer would be more suitable for a given application.
  • Types of plotters currently available. Comparison with printers.
  • Identifying whether a printer or plotter would be more suitable for a given application.
  • Other forms of output. COM. Microfiche. Applications where these might be used.

E. Processor

  • Component parts of the CPU and their functions – ALU, control unit.
  • Main memory and its various forms – RAM, ROM, cache, special purpose RAM e.g. for VDU.
  • Name registers in general use – accumulator(s), program counter (PC), memory address (MAR), memory data/buffer (MDR/MBR), current instruction (CIR).
  • Fetch-execute cycle.
    • Name the steps an instruction passes through in the cycle.
    • Identify how the registers are used for basic instructions.
      e.g. LDA Price, SUB Tax. This topic must be covered in detail.
  • Bus structures.

F. Software

  • Distinction between system software and application software.
  • Distinction between general purpose and special purpose software. Understand that the USER dictates how general purpose software is used.
  • Outline of features of operating systems including systems with multiprogramming facilities. Name different operating systems currently in use and compare in outline.
  • System software.
    • File management software.
    • Utility software. Sort file. Merge files.
    • Language translators. Assembler, compiler, interpreter – basic differences.

G. Filing systems

  • Review of current storage devices – diskette, hard disc, Winchester, flash drive/pen stick, optical devices, digital versatile disk, tape and cassette.
  • The need for buffers and their role in data transfer.
  • Definitions of storage terms – file, record, field, cylinder, track, sector, header label, inter-block gap. Distinction between storage device and storage medium.
  • The structure of data stored on a storage medium.
  • Data transfer checks. Parity and its purpose. Describe odd/even parity with specific numeric examples illustrating acceptance/failure. Cyclic redundancy check.
  • File Organisation and file access
    • Define organisation types – serial, sequential, indexed sequential, random.
    • Distinction between organisation and access. Examples of a file being accessed in more than oneway.
    • For indexed sequential organisations – an understanding of up to 2-levels of indexing.
    • Appreciation that not all record keys appear in the index. How any record can be accessed.
    • Overflow areas.
    • For random access – hashing algorithms. Develop a simple algorithm for a given situation.
    • For each of the four organisation methods, describe the program sequence of steps to:
      • a. access a single record from the file.
      • b. add a new record to the file.
      • c. delete a record from the file.
  • Sequential master file update using an unsorted transaction file. Labelled system flow chart for this process.
  • Selecting the most appropriate file organisation for a given application.

H. Processing

  • Different types of processing – batch and real-time.
  • The role of batch processing with today’s sophisticated systems. Examples of batch processing currently in use.
  • Real-time systems – examples of current use.

I. Security and privacy

  • Security defined as the safeguard of hardware, software and data.
  • Distinction between security and privacy.
  • Realistic methods of data security – securing against
    • accidental damage or loss of data.
    • deliberate sabotage.
  • Methods of achieving good privacy of data.
  • Determining the security/privacy required for a given situation.