Languages and Enviroment Flashcards
What is machine code?
- A language that all processors understand.
- Binary.
What is hexadecimal code?
The lowest form of programming language used by programmers.
What is assembly code?
- Created by the developers of processors.
- Architecture dependent, not portable
- Often used when high performance is crucial
Why are low level languages used?
- Optimisation of code
- Where no translate software exists
- Greater control of hardware features
What are some high level language characteristics?
- Require translation
- Portable
- Easier to read, write and maintain as commands are similar to English
- Allow access to module libraries
- Use data types and data structures, selection statements and repetition/ iteration constructs.
- Use logic operators and functions that are built into the language
- Held in RAM when a program is executed
What is procedural language?
- Designed to allow programs to create code that will be processed logically and in a structured order
- Code is contained within procedures
- Procedures will be created to allow a series of steps to be followed
- Data can be passed from procedure to procedure using parameters
What is declarative language?
- Often used but intelligent systems
- Programmers will create a knowledge base
- A knowledge base contains a series of related facts and rules
- Achieve their effect by the evaluation of expressions
- Allow for the use of self modifying code
- Use capital letters as a variable to find an unknown
What are rules?
- Conditional facts
- Contain goals and sub-goals e.g
likes(alan,pizza)
What is twos compliment?
A process where you convert all the 0s to 1s and all the 1s to 0s, then you add 1.
Describe floating point representation.
• If bytes for mantissa go up:
- the precision goes up
- but the range goes down
• If bytes for mantissa go down:
- the precision goes down
- but range goes up
What is ascii?
- Used 7 bit represent the characters found on keyboards.
- Represents: - 128 characters
- 33 non printing
- 95 printable
What is Unicode?
- 16 bits
- supports 65536 characters
- the first 256 characters in Unicode are used to represent those of ex-ascii
What is sample rate?
Dictates how many samples are taken per second and is measured in KHz
What is sample size?
Dictates how many bits are used to store each sample, much like the concept of bit depth in relation to a bit mapped graphic
What is frame rate?
The term used to describe the number of frames that are captured per second when recording a video.
