A Level Computing – A2 Component 2 1f, 1g, 1h, 1i, 1j

Learning intentions Learners will readdress their understanding of the fetch-execute cycle including how data can be read from RAM into registers. Learners will develop an understanding of assembly language programming Learners will readdress their understanding of Input and Output methods in contemporary computer systems

Assessment outcomes 1f - Describe the fetch-execute cycle, including how data can be read from RAM into registers. 1g - Write simple programs in assembly language and demonstrate how these programs could be executed. 1h - Describe the use of contemporary methods and their associated devices for input and output. 1i - Explain the use of these methods and devices in contemporary computer systems and their suitability in different situations. 1j - Describe and differentiate between voice input for command and control systems to operate a computer system, vocabulary dictation systems for general input and voice print recognition for security. Discuss the suitability of each system in different situations.

Recap: 1F, 1H, 1I, 1J 1f - Describe the fetch-execute cycle, including how data can be read from RAM into registers. 1h - Describe the use of contemporary methods and their associated devices for input and output. 1i - Explain the use of these methods and devices in contemporary computer systems and their suitability in different situations. 1j - Describe and differentiate between voice input for command and control systems to operate a computer system, vocabulary dictation systems for general input and voice print recognition for security. Discuss the suitability of each system in different situations. Task: Work through the questions for 1F, 1H, 1I, 1J. You can use the notes to help Extension: There are grade A Extensions available in 1B and 1C. Complete all of the base questions before attempting these.

1G - Write simple programs in assembly language and demonstrate how these programs could be executed. An instruction set is a collection of instructions that the CPU uses to carry out its tasks. For example, an instruction might look like: 'Add ACC, 3'. This instruction tells the CPU to add 3 to the accumulator. Each make of CPU will have its own unique instruction set which will contain hundreds of complex instructions. A single CPU instruction consists of a binary number, this is called machine code. The machine code is denoted in Hexadecimal format, for example Hex '04D3'

1G - Write simple programs in assembly language and demonstrate how these programs could be executed. Programming in machine code is very difficult because it just looks like a set of numbers making it hard for a human to read and understand. To make things easier for programmers, the chip makers provide an 'Assembly Language' for their CPU which means that programming code can be written in a readable form. For example: The command ADD #3 tells the CPU to add 3 to the current value in the accumulator. This is clearly easier to understand compared to '04D3'. The programmer writes their code in assembly language and this file is then applied through a linker and translator to create the machine code which is loaded into the CPU. Each command in assembly language is called a 'mnemonic'. Machine Code Assembly Language 04D3 ADD #3

1G - Write simple programs in assembly language and demonstrate how these programs could be executed. Complete the Graded Exercises for 1G. You should create a development log style document to explain what each line of your code does in little man computer. http://peterhigginson.co.uk/LMC/ E.g. INP Input a number STA 99 Store number in location 99 INP Input a second number (this does not need storing because only 2 are being added) ADD 99 Add the number stored in location 99 OUT Output the number in accumulator HLT End program

Crib Sheets For your exam you will need to create crib sheets that cover each section. Create a crib sheet that details the key facts that you need to know about 1F-J. 1f - Describe the fetch-execute cycle, including how data can be read from RAM into registers. 1g - Write simple programs in assembly language and demonstrate how these programs could be executed. 1h - Describe the use of contemporary methods and their associated devices for input and output. 1i - Explain the use of these methods and devices in contemporary computer systems and their suitability in different situations. 1j - Describe and differentiate between voice input for command and control systems to operate a computer system, vocabulary dictation systems for general input and voice print recognition for security. Discuss the suitability of each system in different situations.

Pre-Reading 1q, 1r Make notes on 1Q and 1R. Notes can be found in the pre-reading folder and on SMH. You should complete the questions attached to SMH.