9608_w20_qp_12
A paper of Computer Science, 9608
Questions:
7
Year:
2020
Paper:
1
Variant:
2
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1
Different types of data can be represented in a computer system. Numeric is one type of data. Convert the following denary number into Binary Coded Decimal (BCD). Convert the following two’s complement binary integer into denary. Convert the following hexadecimal number into denary. AB Character is another type of data. The following tables show part of the ASCII code character set. Character Denary value Character Denary value A a B b C c D d E e Describe how the computer uses ASCII codes to represent characters. Convert the following string into ASCII codes. Bed Give the denary ASCII code for the following character. H
1. Theory Fundamentals  →  1.1. Information representation
2. Fundamental Problem-solving and Programming Skills  →  2.2. Data representation
Open
3
Complete the following statements about CPU architecture by filling in the missing terms. The Von Neumann model for a computer system uses the program concept. A program is a series of instructions that are saved in . The processor each instruction, it and then it. The processor uses several to store the data and instructions from the program because they can be accessed faster than main memory. The following table shows assembly language instructions for a processor that has one general purpose register, the Accumulator (ACC). Instruction Explanation Op code Operand LDD Direct addressing. Load the contents of the location at the given address to ACC. LDM #n Immediate addressing. Load the denary number n to ACC. LDI Indirect addressing. The address to be used is at the given address. Load the contents of this second address to ACC. STO Store contents of ACC at the given address. ADD Add the contents of the given address to ACC. CMP Compare the contents of ACC with the contents of . OUT Output to screen the character whose ASCII value is stored in ACC. INC Add 1 to the contents of the register (ACC or . JPE Following a compare instruction, jump to if the compare was True. JPN Following a compare instruction, jump to if the compare was False. END Return control to the operating system. The current contents of the main memory are: Address Instruction LDD 80 ADD 80 STO 80 LDD 82 INC ACC STO 82 CMP 81 JPN 50 LDD 80 OUT END … ASCII code table (Selected codes only) ASCII Code Character & ‘ ( ) * Assembly language instructions can be put into groups. Tick (✓) one box in each column to identify the appropriate instruction group for each of the three assembly language instructions. Instruction group Assembly language instruction STO 80 JPN 50 INC ACC Input and output of data Data movement Arithmetic operations Unconditional and conditional jump instructions Compare instructions
1. Theory Fundamentals  →  1.4. Processor fundamentals
Open
5
A teacher uses a relational database, RESULTS, to store data about her students and their test results. Describe the benefits to the teacher of using a relational database instead of a file-based approach. The teacher sets up the RESULTS database using a Database Management System (DBMS). Explain the ways in which the developer interface of a DBMS will help the teacher set up the database. The DBMS creates a data dictionary for the RESULTS database. Identify three items that will be included in the data dictionary. The RESULTS database has the following structure: STUDENT(StudentID, FirstName, LastName, Class, TargetGrade) TEST(TestID, Topic, MaxMarks) STUDENT_TEST(StudentID, TestID, Mark) Complete the following table by giving one example of each database term from the database RESULTS. Give both the field name and the corresponding table name. Database term Field name Table name Primary key Foreign key Attribute Tick (✓) one box to identify whether the database RESULTS is in 1NF, 2NF or 3NF. Justify your choice. 1NF 2NF 3NF Justification: Complete the Data Manipulation Language (DML) script to display the Student ID, mark and maximum marks for all tests with the topic of ‘Programming’. SELECT StudentID, Mark, FROM STUDENT_TEST, Topic = "Programming" AND = ; The teacher wants to implement validation to make sure that all data entered into the database RESULTS are reasonable. Name three different methods of data validation that can be used in the RESULTS database. Describe how each method will limit the data that can be entered in this database. Method 1 Description Method 2 Description Method 3 Description The teacher stores the database on the desktop computer in her classroom. Explain why it is important to keep the database secure. Explain the ways in which the teacher can use data backup and disk mirroring to limit the amount of data lost in the event of hardware failure. Data backup Disk mirroring
1. Theory Fundamentals  →  1.8. Database and data modelling
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6
Malika has started a new job as a trainee software engineer. Malika’s manager has asked her to work with a senior software engineer for the first week. Explain the ways in which Malika’s manager has acted ethically. Malika researched the company and the programming languages used by the company before she started the job. Explain the ways in which Malika has acted ethically. Malika thinks that her colleagues do not like her, so she asks her manager for help. Describe the actions the manager could take to support Malika in an ethical way.
1. Theory Fundamentals  →  1.7. Ethics and ownership
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7
A web server has a public IPv4 address. Draw lines to link each characteristic to its appropriate IP address. Can use hexadecimal notation Characteristic IP address Each group of digits is a number between 0 and 65535 IPv4 IPv6 Consists of four groups of digits Uses double colons (::) The total length of the address is 32 bits IP addresses can be static or dynamic. Explain the reasons for the web server using a static instead of a dynamic IP address.
1. Theory Fundamentals  →  1.2. Communication and Internet technologies
3. Advanced Theory  →  3.2. Communication and Internet technologies
Open