Information Processing - Main Topics of Study
- 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.
- 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.
- 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.
- 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.
- 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.
- 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.
- 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.
- 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.
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.
Refer to the ICM website for learning material.
Alternative texts & Further Reading:
Computer Science for Advanced Level by R Bradley – (Stanley Thornes) - (Fourth edition).
A Level Computing by PM Heathcote & S Langfield – (Payne Galloway) - (Fifth edition)