Midterm 1 - hardware

Question 1

what is caching

Answer 1

caching is the process of retrieving information from a slower storage system and placing it in a faster storage so that it is readily accessible to a program

Question 2

how many caches exist

Answer 2

secondary storage (slowest, largest)
memory/ram
L3
L2
L1 (fastest, smallest)

note: L cache is specifically stored directly by the CPU itself

Question 3

how does a CPU use few basic operations, but extremely quickly

Answer 3

• uses arithmetic logic –> a bunch of AND + OR gates

OR = inclusive “either or both”
XOR = exclusive “either, but NOT both”

• control flow of logic to organize data movement

since the arithmetic is very simple –> can be done extremely quickly
since LOTS of arithmetic is done so quickly, easily capable to scale up to very complex operations

Question 4

what are the key CPU characteristics (4)

Answer 4

CCCP

of cores –> how much multitasking can be done at once

core clock (hz) –> how quickly tasks can be performed

cache size –> how much information can be stored on a moments notice

power consumption

Question 5

logic gate symbols

Answer 5

bullet = AND
arrow = OR
reinforced arrow = XOR

(practice)

Question 6

secondary storage vs primary storage

Answer 6

differences: speed, size, permanence, connectivity

secondary = recgular drive storage –> very large, relatively slow to access data from

primary = ram –> fast access, small storage

CPU can only utilize data on primary/ram –> data on secondary is inaccessible

secondary does not require continuous power supply to retain info –> permanence
primary (ram) requires power. power off –> primary is wiped clean

Question 7

how does a PC use secondary storage

Answer 7

program requests data from primary –> data is pulled into ram and therefore accessible to program (caching)

program no longer uses the data –> data is overwritten for more immediate tasks and therefore must be re-retrieved (re-cached)for later use

Question 8

define peripheral

Answer 8

hardware not technically required for the PC to function. includes interaction and non-interaction stuff

eg monitor keybaord, wifi router, GPS, sensors

Question 9

event driven vs polling peripherals

Answer 9

differentiated based on how/when they send/recieve signals

event-driven –> only sends signals when an action has occurred (eg keyboard)

polling –> continuously sends data, usually for monitoring/sensing changes in values (eg GPS)

Question 10

software: application vs system program

Answer 10

programs/services are required for computer operations (eg drivers), usually operate in the background

applications are software that is intractable (eg games, media editors)

Question 11

components of any software

Answer 11

instructions - how the program will utilize data –> logic control + flow

data - inputs the program will recieve, outputs it will return (eg textures, audio files, stored data files)

OS requests - what sorts of system resources the program will require –> must request access + allocation of resources from OS (eg X program requires X ram, Y storage space)

Question 12

example of OS requests

Answer 12

• access + allocation of RAM
• access for user settings stored in a file from secondary storage (request to move file to RAM)
• request access to server through specific ports
• request to access/modify core system files

Question 13

components of an OS (3)

Answer 13

kernel
bundled apps
shell

Question 14

OS - kernel

Answer 14

systems resource management –> quartermaster
responds to app requests –> sends authorizations for system access

AUTHORIZATIONS TO SAVED DATA + INTERNET ACCESS

therefore critical to security –> prevents malware from readily overtaking system

Question 15

OS - bundled apps

Answer 15

pre-installed programs that come with the OS

includes critical sys files + bloatware