OCR H446/01 – 1.2 Software and software development

(a) The need for, function and purpose of operating systems.
(b) Memory Management (paging, segmentation and virtual memory).
(c) Interrupts, the role of interrupts and Interrupt Service Routines (ISR), role within the Fetch-Decode-Execute Cycle.
(d) Scheduling: round robin, first come first served, multi-level feedback queues, shortest job first and shortest remaining time.
(e) Distributed, embedded, multi-tasking, multi-user and Real Time operating systems.
(f) BIOS.
(g) Device drivers.
(h) Virtual machines, any instance where software is used to take on the function of a machine, including executing intermediate code or running an operating system within another.

(a) The nature of applications, justifying suitable applications for a specific purpose.
(b) Utilities.
(c) Open source vs closed source.
(d) Translators: Interpreters, compilers and assemblers.
(e) Stages of compilation (lexical analysis, syntax analysis, code generation and optimisation).
(f) Linkers and loaders and use of libraries.

(a) Understand the waterfall lifecycle, agile methodologies, extreme programming, the spiral model and rapid application development.
(b) The relative merits and drawbacks of different methodologies and when they might be used.
(c) Writing and following algorithms.

(a) Need for and characteristics of a variety of programming paradigms.
(b) Procedural languages.
(c) Assembly language (including following and writing simple programs with the Little Man Computer instruction set).
(d) Modes of addressing memory (immediate, direct, indirect and indexed).
(e) Object-oriented languages with an understanding of classes, objects, methods, attributes, inheritance, encapsulation and polymorphism.