Flashcards
FINAL FORM
Cards in this deck (18)
- 1What are the recursive steps required to use the map functionMap applies the function to each item in the list. It applies the function to the head of the list, then makes a recursive call on the tail of the list.
- 2Disadvantages of parallel communicationMore wires required
-More expensive
-Harder to replace and maintain
Data needs to be kept synchronised across wires/Data skew/Cross talk
-More chance of errors
-Limiting factor of transmission speed as the problem worsens at higher speeds - 3Why could internet be slower at public space than at home?In public space, speed could be limited for each device that is connected
-More clients connecting to one access point
-Less bandwidth
-More collisions - 4How can bitrate be higher than baud rate?Each signal change represents more than one bit of data
- 5Physical vs logical topologyThe physical arrangement of the wires between devices, and the arrangement of the devices
Logical - how data flows around a network and the type of protocol used - 6Peer to peer vs Client ServicesClient Server:
-Resources stored on the server
-Clients request resources/services from server
-Centralised login/security/administration
Peer to peer:
- Resources stored on each individual computer
-Each comp has equal status
-Each computer can access resources from each other - 7Examples of hexadecimal being usedUsed to represent colours, MAC addresses.
It is used as it provides a shorter, easier to read, representation of a number than binary. - 8SSD compared to Hard DriveSSD has faster read/write times
SSD has lower power consumption
SSD has lower latency
Quieter
Less heat
Less vulnerable to damage from physical impact
Hard disk:
Cheaper per GB
Have been used for longer so greater confidence about storing data long term - 9SSDChips containing NAND flash memory and a controller that manages reading and writing. Data is stored by floating gate transistors that trap and store charge. Does not loose data when power is turned off. Data cannot be overwritten easily. An entire block must be removed for each change, reducing the lifespan of the flash memory. The controller minimises this by spreading out the data across all available flash memory.
- 10Why use harvard over von neumanData and instructions can be accessed simultaneously as they are stored in sperate memory. Avoids data being executed as code (used by hackers). Instructions and data can have different word length
- 11ADV of high lvl langEasier to debug
One line of high lvl can do an operation that takes many lines of low lvl
It is faster to produce programs/Programmers can be more productive
Built in support for data structures - 12Principles of operation of an optical diskA spinning disk, coated in reflective film
The film has land or pits.
Light is shone at the disk
Some light is reflected back
Amount of reflected light is measured by a light sensor
Disc spins at a constant linear velocity
Data is stored on one track
Land reflects light whereas put scatters light
Land represents a 1, pit i, or vice-versa - 13Challenges that face legislators in the digital ageInformation can be transferred in ways that were not previously possible
Technology evolved quickly so difficult for law to keep up with changes
Global nature of internet means crimes may be committed in one country to someone in another. The laws are national so countries have different laws
Methods such as encryption means its harder to monitor criminal activity
Some crimes committed by states rather than individuals
Harder to gather digital evidence - 14Describe an example of a problem that could occur if no system were in place to manage concurrent access to the database.Two users can simultaneously update a record. Whilst one user saves their changes, the other user can save afterwards, losing the first changes made by the first person.
- 15Describe the role of interrupts.Pauses a currently running program
To run a high priority routine such as an urgent error that needs to be dealt with. Sends a hardware interrupt to the processor and memory registers are backed up and restored afterwards. - 16Why must registers be backed up before interupt?So that their contents can be restored afterwards and the program can continue running as before. As the interrupt routine will override whatever is in the registers
- 17Magnetic Hard DriveA spinning platter of disks, with magnetically charged particles. The polarity of the particles represents a 1 or 0. There is a drive head which must move over the disk. It is a mechanical component.
They spin at a constant linear velocity.
A read head detects the polarity. - 18How domain names are organsiedDomain names are structured into a hierarchy fashion with small domains appearing lower down. When written out you work from the bottom up.
Information
- Description
- Flashcards on FINAL FORM, created by James John on 19/06/2022.
- Created by
- James John
- Views
- 5
- Rating