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.
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.
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.
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.
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).
- Bus structures.
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.
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.
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.
- 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.
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.
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.
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: (a.) accidental damage or loss of data. (b) deliberate sabotage.
- Methods of achieving good privacy of data.
- Determining the security/privacy required for a given situation.
Example Candidate Response Booklet
Example Candidate Response (ECR) Booklets are a source of crucial information for Centres and Candidates as they use real candidate responses. We ask Senior Examiners to comment on five or more responses in terms of why the mark was awarded with commentary about how to improve the answer (if necessary).