paper 1 Flashcards
what is a computer
A machine that processes data
define hardware system
the physical stuff that makes up a computer system: monitor, motherboard
what is an embedded system?
computers inside of a larger system. They are usually systems dedicated to one task
what is a control system?
manages, commands, and directs other devices or systems
explain the role of the control unit in the CPU
its main job is to execute program instructions by following the fetch-decode-execute cycle
what are the three names of the registers in the CPU
MAR, MDR, ACC
What does ALU stand for and what does it do
Arithmetic Logic Unit - does all the calculations
what is the cache and what is it used for
the cache is very fast memory in the CPU that stores regularly used data so that the CPU can access it quickly
describe what happens at each stage of the CPU fetch-decode-execute cycle
fetch- copy memory address from the program counter to the MAR and then copy the instruction stored in the address to the MDR
decode- instruction in MDR is decoded by the CU. The CU may then prepare for the next step by placing values into MAR or MDR
execute- the instruction is performed
how does clock speed affect CPU
clock speed is the number of FDE cycles that the CPU can carry out
how does the number of cores affect the CPU
more cores mean a greater number of instructions can be processed in a given time
how does cache size affect the CPU
bigger cache means less time the processor has to wait for instructions to be fetched
What is the purpose of the CPU
it processes all of the data and instructions that make the system work
what is the MAR
holds any memory address about to be used by the CPU
what is the MDR
Holds the data or instruction fetched or waiting to be written to memory
what is the program counter?
Holds the memory address of the instruction for each cycle
what is the difference between volatile and non-volatile memory?
volatile memory is temporary
non-volatile memory is permanent
what does RAM stand for and how is it used in a computer system
RAM is a high-speed, volatile memory that stores data while they’re being used
could changing the amount of RAM affect the computer’s performance?
It would increase the performance of the computer because it wouldn’t need to use virtual memory as often
when and how is virtual memory used?
Virtual memory may be needed if too many applications open at once.
when RAM is full the computer moves data that hasn’t been used recently to a location on secondary storage
explain why ROM is required by a computer system
ROM is a non-volatile memory that contains all the instructions a computer needs to properly boot up. This is called the BIOS (basic input-output system)
state three characteristics of a processor that could affect its performance
clock speed
cache size
number of cores
state three components of a computer system that could be upgraded
RAM
GPU
CPU
define primary storage
memory areas that the CPU can access quickly
define secondary storage
where all data is stored when not in use and they are much slower than primary storage
list four uses of flash memory
USB memory sticks
mobile phones
video game hardware
digital audio players
is SSD better than HDD?
SSD’s have no moving parts so they are quieter and more robust. They are also significantly faster. However, they are more expensive and have a lower average capacity
why might someone choose magnetic tape as a form of storage?
it has a great storage capacity at an extremely low cost. It can be used by large organizations to store huge amounts of data.
what are the pros and cons of optical storage
+cheap +portable +won’t be damaged by water or shocks
-low capacity -slow read/write speed
what are the pro and cons of magnetic storage
+high capacity +cheaper than SSD +high speed
-moving parts -less robust than SSD
what are the pros and cons of solid-state drives (SSD)
+faster than HDD +reliable +robust
-expensive
