Computer Science Paper 1
🇬🇧
In English
In English
Practice Known Questions
Stay up to date with your due questions
Complete 5 questions to enable practice
Exams
Exam: Test your skills
Test your skills in exam mode
Learn New Questions
Manual Mode [BETA]
The course owner has not enabled manual mode
Computer Science Paper 1 - Leaderboard
Computer Science Paper 1 - Details
Levels:
Questions:
107 questions
| 🇬🇧 | 🇬🇧 |
| - Directs the flow of data between the CPU and other devices - Fetch, Decode, Execute | What two tasks are the Control Unit responsible for? |
| - Address Bus - Data Bus - Control Bus | What are the 3 buses in a CPU? |
| System Bus | What is the name for the three buses collectively? (Address bus, Data bus, Control bus) |
| A collection of Control Lines | What makes up the Control Bus? |
| Handles commands to other devices | What does the Control Bus do? (generally) |
| Moving data and instructions between system components | What is the Data Bus responsible for? |
| Controls where the Data Bus is going to or from | What does the Address bus control? |
| - Accumulator - Program Counter - Current Instruction Register - Memory Address Register - Memory Data Register | Name the 5 registers in the CPU |
| Program Counter (PC) | The Address of the NEXT instruction to be executed is held in which register? |
| Current Instruction Register | Which register holds the current instruction being executed? |
| - opcode - operand | What is the data in the current instruction register divided into? (two things) |
| The address of the memory location from which data is to be fetched or written | What is stored in the Memory Address Register? |
| The actual data read from or written to memory | What is stored in the Memory Data Register (MDR)? |
| Memory Buffer Register | What is another name for the Memory Data Register? |
| - Clock Speed - Number of Cores - Cache Memory (amount and type) | Name the 3 main factors which affect processor performance |
| 3.5 billion cycles per second | How many cycles per second with a clock speed of 3.5GHz? |
| 2-4GHz | What is the average clock speed? (between two values) |
| Software may not be capable of taking advantage of multiple cores | Why does doubling the number of cores not necessarily double performance? |
| When an instruction is fetched from Main Memory | When is data copied to the cache? |
| Level 1 is faster but smaller | There are different levels of cache - Level 1 and Level 2. Which one is faster and what is the drawback of it? |
| Fetching a new instruction at the same time as the previous is being decoded and executed - performing the different stages of a process in parallel like an assembly line | What is Pipelining? |
| - Instruction Pipeline - Arithmetic Pipeline | Processor Pipelining is sometimes split into two subs, what are they? |
| A group of bytes | What is a word? (in the context of buses) |
| Harvard | What is the other architecture other than Von Neumann? |
| Digital Signal Processing (DSP) - audio and speech signal processing, sonar etc | What is Harvard Architecture often used for? |
| Harvard Architecture | In which architecture are Data and Programs held in seperate memories? (Von Neumann or Harvard) |
| Data and instructions can be fetched in parallel instead of competing for the same bus | In what way can Harvard architecture be faster than Von Neumann? |
| - Clock Speed - Number of Cores - Cache size - RAM size - GPU - Pipelining | What are the 6 factors which affect CPU performance |
| - Overheating - Transistors aren't any faster | Why haven't clock speeds increased past 3.5GHz-4GHz? (2 reasons) |
| Heat Sink | What's the bit that keeps the CPU from overheating? |
| - Larger and more specific instruction set so programming is simple - But the hardware is more complex as a result (uses more power) | What is one advantage and one disadvantage of CISC? |
| Simpler instruction set means simpler hardware but more complex software | What is the tradeoff with RISC? |
| RISC because each instruction takes only one clock cycle to complete so tasks can be efficiently scheduled and completed in parallel | Which one is better for pipelining (CISC or RISC) and why? |
| CISC | Which one (RISC or CISC) is usually used in desktop computers and laptops? |
| RISC | Which one (RISC or CISC) is usually used in smartphones? |
| Has several ALUs | What is special about an array processor? |
| GPUs have thousands of smaller, more efficient cores which process in parallel | A CPU has a few cores optimised for sequential processing, what about GPUs? |
| - A co-processor is used to offload compute-intensive parts of an application to the co-processor while the remainder of the code runs on the CPU. - A GPU is an example of a co-processor | What is a co-processor used for and what is an example of a co-processor? |
| - Pen-type - Laser Scanners - CCD readers - Camera based readers | What are 4 types of barcode scanners? |
| Pen-type readers are the most durable type BUT they need to come into physical contact with what they're reading to work | What type of barcode reader is the most durable and what is the drawback of it? |
| - Barcode Readers - biometric devices - sensors | Give 3 examples of automatic input devices? |
| Can store lots of data cheaply but is inconvenient to move around | One advantage and one disadvantage of magentic storage |
| Portable and cheap but small capacity and easily damaged | Two advantages and two disadvantages of optical storage |
| - Backup is a precaution against losing data - Archiving is storing rarely used data to free up space | What's the difference between backup and archiving? |
| Pits and lands - Pits are burned into the disk's surface with a laser making it less reflective at those points. pit = 1 land = 0 | How is data stored on optical storage? |
| Blu-Ray has shorter wavelength in the laser which allows much smaller pits to be engraved which means more can be fit in a smaller space | Blu-Ray vs CD ROM - Which has higher capacity and why? |
| They all have a way of representing 1 and 0 without power | What is a similarity between all secondary storage devices? |
| To retain data when the computer is turned off | Why is secondary storage necessary? |
| The platters are coated in magnetic material. The different magnetic poles represent 0s and 1s | How do Hard Disks store data? |
| Use a reflective layer with a transparent dye coating that becomes less reflective when a laser 'burns' a spot in the track | How do recordable disks store data? |
| Use a laser and a magnet to heat a spot on the disk and then set it's state to become a 0 or a 1 using the magnet before it cools again | How do rewritable disks store data? |
| - Fast read/write speed - Power efficient - Less fragile - Silent - More portable | Name 5 advantages of SSDs |
| - Relatively low capacity - Expensive | Give 2 disadvantages of SSDs |
| - remove frequencies too high for most people to hear - remove quiet sounds which happen at the same time as louder sounds | What are 2 lossless compression techniques for audio? |
| Laser scanners | What type of barcode reader is used in supermarkets? |
| Camera-based scanners | What is the most reliable type of barcode reader? (use for Berlin Film Festival Tickets) |
| - RFID (Radio Frequency Identification) - Passive and Active | What is the technology used for oyster cards and what are the two types? |
| Dog tagging | What is another use of RFID tags other than bank cards/oyster cards? |
| OLED is plastic so it can bend | What's the difference between LED and OLED screens? |
| - don't last as long - sensitive to water - slow refresh rate (bad for games) | What are 3 disadvantages of OLED displays? |
| - Thinner - Don't need backlighting - Consume less power | What are 3 advantages of OLED displays? |
| - they're decent quality and FAST - They use toner as ink | What's the good thing about laser printers and what type of ink do they used? |
| - Inkjet - Works by spraying minute dots on the page | What type of printer is very high quality and how does it work? |
| Moving an aileron | What is a use of an actuator in the context of a plane? |
| Blu-Ray has shorter wavelength in the laser which allows much smaller pits to be engraved which means more can be fit in a smaller space - higher capacity | Which has higher capacity and why? (CD-ROM or Blu-Ray) |
| - Bootstrap loader - a small program that starts up as soon as the computer is switched on and causes the OS to be loaded | What is something which is stored in ROM and what does it do? |
| To bridge the user and the computer hardware, since the user cannot communicate with the hardware directly | What is the purpose of an operating system? |
| - Control Hardware - Manage software (loading into RAM) - Provide security (username and password) - Provide user interface - Processor scheduling | Name 5 functions of an operating system |
| - Kernel - Drivers - User Interface - System Utilities | Name the 4 main parts of an OS |
| Paging is fixed size (4Kb) segments, segmentation is varying length segments | What's the difference between paging and segmentation and how big is a page? |
| - Pages are fixed size | What is one difference between pages and segments? |
| The allocation of segments or sections of memory to allow a process to run | What is memory segmentation? |
| . | What are the types of scheduling algorithms? |
| To compensate for the difference in speed between the peripheral and the CPU | What is the point of a buffer (in the context of peripheral management) |
| The memory manager determines the least used page and copies it into virtual memory. The free area is re-numbered by the memory manager and marked as free for use | (paging) What happens if RAM is full but more pages are needed? |
| Quickly loading and unloading things from RAM | What causes disk thrashing? |
| When memory locations get 'locked up' because the data isn't properly flushed so the memory manager thinks it's still in use | What is a memory leak? |
| When a stack gets too full and runs out of free memory to use | What is stack overflow? |
| At the end of each fetch-decode-execute cycle | When does the CPU check for interrupts? |
| When all registers are copied to the stack before executing an interrupt | What is context switching? |
| Stack overflow because each paused instruction is put in the stack until it is resumed so eventually the stack can overflow | What is a risk of too many interrupts interrupting other interrupts? |
| - Doesn't take into account how important a process is - Doesn't consider that some processes are long and some are short | What are 2 disadvantages of round robin scheduling? |
| Each one is allowed to complete before moving on | What is first come first served scheduling? |
| - Doesn't account for processing time - Doesn't account for priority | What are 2 disadvantages of first come first served scheduling? |
| Maximum number of jobs completed quickly but long jobs may never complete if shorter jobs keep interrupting | What is one good thing and one bad thing about shortest job first scheduling? |
| Shortest Time Remaining | Name the scheduling algorithm which fixes shortest job first's problem |
| Multi level feedback queue | What scheduling technique takes priority into account? |
| Multi-tasking OS | What is this type of OS called? - Windows, Linux, MacOS |
| Allocates each workstation time | How do multi-user OS' allow multiple workstations to access the mainframe? |
| Multiple computers all being controlled by one OS and sharing a task (spreading the workload) | What is a distributed OS? |
| - It must respond very quickly to any inputs or sensors - It must be able to deal with many inputs simultaneously - It must have "failsafe" mechanisms to detect and take appropriate action if a hardware component fails - It must incorporate redundancy - if one component fails, it needs to automatically switch to backup hardware - Used on planes and factory production lines | What are the 4 required features of a real-time OS and what are 2 examples of somewhere a realtime OS would be used? |
| - ATM - Washing - Car | Name 3 devices with embedded OS |
| The low-level real-time operating system in charge of radio and other hardware has system vulnerabilities | What is a problem with smartphones having 2 operating systems? |