High level code v machine code questions and answers
Q1. In computing, what is a ‘bit’ and a ‘byte’?
A1. A bit is a single unit of storage. It holds a one or a zero. A byte is a group of eight bits.
Q2. What is meant by ‘machine code’?
A2. Every computer has a processor. That processor has a fixed number of instructions which it can carry out. All of the instructions together, which a particular processor can carry out, is known as the 'machine code' for that processor. Any particular instruction can be represented as a binary pattern.
Q3. What is an ‘assembly program’?
A3. Instead of writing in binary patterns, which corresponded to machine code instructions, programmers wrote in 'mnemonics' e.g. SUB 65.
Q4. What is a ‘mnemonic’?
A4. An easy-to-remember code for a machine code instruction.
Q5. What has to be done to an assembly program before a processor can run it?
A5. It needs to be translated into machine code. This is done using an assembler.
Q6. What is meant by a ‘reserved word’?
A6. Any particular programming language has a set of these special keywords and the programmer can use them to write programs and make the processor behave in a certain way, but they can’t use them as names for constants and variables, for example. These keywords are also known as ‘reserved words’.
Q7. What is source code?
A7. This code the programmer has written.
Q8. What is object code?
A8. This is code after is has been translated, that the CPU can understand and run.
Q9. What is a low level language?
A9. A low level language is one where the instructions are very close the machine code instructions that the CPU understands.
Q10. How does a high level language differ from a low level language?
A10. This is any programming language that uses English-like words for the programs.