A451

HideShow resource information
2.1.1(a)What is a computer system?
A system that is able to take a set of inputs, process them and create a set of outputs using a combination of software + hardware.
1 of 81
2.1.1(b)How are computers used in the home to automatically control various systems and reduce workload?
By using embedded systems (where a comp processor is integrated into a device for automatic control purposes) i.e. washing machines, central heating control, burglar alarm, dishwashers etc.
2 of 81
2.1.1(b)How are computer systems used in commerce and business?
Most organisations use it for; basic office functioning, interpersonal communication and ecommerce. i.e. teleworking, videoconferencing, cloud computing, collaborative working, website creation + online sales.
3 of 81
2.1.1(b)How are computer systems used in medical systems?
Used by doctors/hospitals to treat/diagnose illnesses i.e administration, diagnostics with scanners + radio therapy.
4 of 81
2.1.1(b)Computers are used in embedded systems, home entertainment + communications, commerce + business and medical systems. Where are computer systems also used in the modern world?
Comp systems also used in education + schools, banking + finance, government, leisure clubs + venues & military application.
5 of 81
2.1.1(c)What is reliability and robustness?
The ability of the computer system to perform the required functions without failure. This can be measured by MTTF. Mean Time to Failure - average number of hours that the system can run for before it fails/break down.
6 of 81
What is another way of measuring reliability?
AVAIL Percentage of time system is available to user/customer (excluding any planned downtime for i.e. maintenance)
7 of 81
Why is it important that computer systems are both robust and reliable?
As unreliable systems may fail/crash which could be serious in a medical situation or trade + in businesses. If not robust the system may hang which may prevent a customer completing a transaction
8 of 81
2.1.1(d)Why is it important to make energy use efficient and how can this be done?
As energy supplies are expensive. Reduce the heat created in new computer systems or reuse the waste heat from data centres to heat other parts of the building –reducing the overall energy usage + impact on climate change.
9 of 81
2.1.1(d) Name three automatic energy-reduction techniques within the workplace?
Use of low-energy devices for lighting, improved heating controls automatically take account of which rooms need to be heated + at what level, Lights can be switched off automatically in individual offices when no one is in the room.
10 of 81
2.1.1(d)How can the sustainability of finite resources be maintained in the computer industry by increasing the use of sustainable resource?
Use of electronic comm rather than postage service (SMS, emails etc. increasing speed of comm). Reducing commuting needed, fuel costs + consumption by videoconferencing/teleworking. Operating the business based on a paper-free approach.
11 of 81
2.1.1(d) What was the data protection act 1998?
Introduced 1998 to ensure that the data held on clients conformed to certain principles such as being held securely, being up to date and not being kept longer than necessary.
12 of 81
2.1.1(d) Give examples of software methods to help protect client data.
Passwords (strong + hard to break), encryption (used to make stored data more secure by making it unreadable to people without the key to decode it usually to protect data transmitted over the internet) + selective drop down menus
13 of 81
2.1.1(d) What was copyright Design and Patents Act?
Introduced 1988, aimed to protect the intellectual property of individuals and organisations that create and produce materials based on their own individual ideas.
14 of 81
2.1.1(d) What was the Computer Misuse act 1990?
Introduced with the express purpose of preventing attacks on ICT systems to commit crimes or to damage the system - made hacking + the introduction of a comp virus into criminal offences.
15 of 81
2.1.1(d) What is hacking?
The practice of breaking into comp systems. Essential that preventative measures (i.e. firewall-used to prevent unauthorised requests from hackers to gain access to network/comp systems via internet + intrusion detection is set up) are taken.
16 of 81
2.1.1(d)What are viruses + spyware?
Viruses: programs designed to cause damage to a computer (risk minimised by virus-scanner/anti-virus software—scans + deletes once detected) Spyware: programs that run in a comp system to gather info + pass it on to other interested parties.
17 of 81
2.1.1(d)What are Intrusion Detection Systems (IDS)?
Designed to monitor the network/computer system for malicious activities. Once an incident is detected, a report is produced + sent to the network management for further action to prevent any risk to the system.
18 of 81
What are the 5 aspects of operating systems and what is an OS?
The software that controls the hardware and creates a user interface to run application software – User Interface, peripheral management, Multi-tasking, memory management, Security.
19 of 81
Give examples of Operating Systems.
Microsoft Windows (GUI – Graphical User Interface), Os X (Version of Windows GUI by Apple Inc), Unix, Linux (Commonly used open source OS)
20 of 81
What is the function of systems software?
To control computer hardware and to create a platform to run application software.
21 of 81
When might experts have to use command line interface?
When the situation allows little power. To service/modify a machine in a factory (which only has a basic OS + limited functionality). In the computer industry - system administrators may use it when setting up routers and firewalls.
22 of 81
When are menu driven interfaces used?
When a limited range of options is needed to perform a task i.e. bank ATM
23 of 81
What are the advantages of using Menu driven interfaces?
No training needed to successfully operate the system + the limited choice reduces the risk of getting “lost” or “breaking into the system.”
24 of 81
What is Multi-tasking?
When a user has more than one program open (or loaded into RAM) at the same time. The OS allows the user to switch between programs with each program in a different window.
25 of 81
How can current PCs manufactured with 7 or 9 core processers affect multi-tasking?
Multi-tasking operates more efficiently when the computer has multi-core processers as the CPU processes instructions one at a time in single-core processor.B
26 of 81
Give examples of password requirements a systems administrator can select to aid the system’s security?
Password length of 8 characters minimum, including upper and lower case letters, including a number, including a symbol such as “£” etc.
27 of 81
What does each file have in a multi-user OS such as Linux and Unix?
A full list of access rights or permissions including the option to read, write, execute or any combination of this i.e. No permissions (- - -), Read, write + execute (r w x), Read + Write (r w -), Read and execute (r – x) etc.
28 of 81
What are executable files and access rights?
Executable files are programs of instructions that can be executed or run whilst access rights are settings that allow users permission to read, write and execute files.
29 of 81
Why are file access permissions used?
To maintain + privacy of files i.e. bank customer can only set-up/read their own account details, whereas a member of staff in the bank could read/write to many customer accounts.
30 of 81
What are utility program?
Range of systems software designed to help user manage, maintain + optimise the system incl. file management, memory testing, data compression, anti-virus protection, data synchronisation, disk management + defragmentation + network utilities.
31 of 81
Give examples of utility, security programs?
Antivirus + spyware protection can be provided by a third party to scan the system to detect + remove these rogue program. Firewalls prevent unauthorised internet users accessing private networks connected to the internet (i.e.home c.s.)
32 of 81
Utility programs: Disk organisation: Defragmentation Utility?
This moves all the files on disk to make them contiguous and make sure that all free space is in large continuous blocks as it can improves and speeds up computer performance (as its quicker to access files).
33 of 81
Utility programs: Disk organisation: Formatting?
Involves dividing the hard disk into one or more regions known as logical volumes that can be identified in the file manager as i.e. C Drive, D drive etc. The a file system fomat is created so that the OS can identify the contents of the logical driv
34 of 81
Utility programs: System information and diagnosis?
The OS provides system info for maintenance purposes incl: processor used, BIOS version, amount of physical memory, virtual memory + the boot device. Diagnostic programs test system configuration or hardware i.e Check disk utility
35 of 81
What is “system clean-up tools”?
Utility program that detects and deletes the temporary files that are left on the hard disk after exiting a program which waste a lot of disk space.
36 of 81
What are the several update options in system clean up tools?
Switch off automatic updates/automatically download + install updates/ automatically download updates and let the user choose when to install them or notify user of updates but don’t automatically download or install them.
37 of 81
What is off the shelf software and what are the advantages?
Packages readily available for immediate purchase + installation. Pros: Cheaper due to large number of customer, support available (i.e.websites, forums etc.) + readily available for use from shop + software downloads.
38 of 81
What are the disadvantages of Off-the-Shelf Software?
May be complicated to learn + use and may have features not need, doesn’t give a competitive advantage as all your business rivals will be using the same software + it may not meet all of your business requirements.
39 of 81
What is custom-written software?
Software developed as a particular solution for an organisation. Designed to meet all customer requirements (more efficient), unavailable to business rivals –competitive advantage but takes time to develop + user support is limited (not widely used)
40 of 81
What is open source software?
Software that permits the user to copy, edit + change the software as required. Pros: free, source code continually developed so new features added regularly, source code readily available (can be modified)
41 of 81
What are the limitations of Open Source software?
Expertise is needed if the software needs to be adapted for a particular situation. Open source software normally lacks support, software quality + responsibility to fix bugs not guaranteed, must be distributed in a form that can be read + edited.
42 of 81
What are the advantages of proprietary software?
Licensed to the purchaser + gives the right to use the software but not to modify or redistribute it. Pros: software coded + modified by manufacturer whom normally provides support (help pages, wizards + online vid instruction) + tests system extensi
43 of 81
What are the Limitations of Proprietary software?
Can be expensive as licenses have to be bought for each workstation software is loaded onto. New versions regularly release = pressure + cost involved to upgrade.
44 of 81
2.1.2(d) Why is data represented in computer systems in binary form?
As comp systems comprise electronic devices in which there are 2 states (ON-1, OFF-0). Binary stored in comp systems as different voltage levels (0=low voltage 1= high).
45 of 81
2.1.2(f) What is the truth table + symbol for a NOT gate?
.
46 of 81
2.1.2(f) What is the truth table + symbol for the OR gate?
.
47 of 81
2.1.2(e) What are truth tables and logic gates?
Truth table: diagram that shows all possible logical inputs + their associated outputs. Logic gates: circuits that are used to perform a logical operation in computing.
48 of 81
2.1.2(h) Explain the need for ROM in a computer system.
Used for storing instructions for programs that run when the computer is switched on (i.e.Windows 7). Used for permanent storage + is non-volatile - data is not lost when the system is powered down.
49 of 81
2.1.2(j/k/n) What happens when the RAM is full?
The system’s performance becomes slower and less efficient as it has to make use of virtual memory. As programs start become increasingly memory hungry and production costs decrease, the typical amount RAM increases.
50 of 81
2.1.2(k/l) What is Virtual and Cache memory?
Virtual memory – where the hard disk is used to temporarily store some of the RAM content. Cache memory – A small memory store used directly by the CPU. It holds copies of most frequently
51 of 81
2.1.2(o) What is the need for keyboards?
Most common type of input device normally QWERTY but modern kbs have keys arranged ergonomically to minimise RSI (Repetitive Strain Injury).
52 of 81
2.1.2(o) What are specialised/concept keyboards?
Used in pubs + fast food restaurants, made up of a grid of images for the various drinks/items on the menu. Operator selects appropriate image to enter purchase into ICT system that calculates bill. Also used in primary schools
53 of 81
2.1.2(o) Name some manual input devices?
Mouse (& touch pads + track balls) mainly used a selection tool for data input, touch screen (pro: if interface is well done = intuitive + requires no training. Joysticks used to play com games.
54 of 81
2.1.2(p) Name some more manual input devices?
Microphone (voice recognition which convert sounds into commands), remote control (used to switch on/make selections on devices i.e. TVs), Scanner (handheld/integrated into printer/flatbed), MIDI interface (connect musical instruments to a comp).
55 of 81
2.1.2(p) What are the pros and cons of using a graphic tablet and stylus?
More natural to draw using stylus rather than pen + higher level of accuracy but not ideal for general selection work (i.e. pointing + clicking on menu items)
56 of 81
2.1.2(s) Why do we use secondary storage devices for computer systems?
Computers use RAM as working storage for processing data but it’s volatile (all data is lost when the power is switched off). Secondary storage is used to keep permanent copies of programs.
57 of 81
2.1.2(t/u) What are advantages and disadvantages of using magnetic tape to store data?
Low cost, high capacity(80MB-1TB), portable design in cassette tapes, normally used for backup or archiving, reliable if carefully stored but it’s a serial device (slow speed) + tape can be damaged by repeated use.
58 of 81
2.1.2(t/u) What are the pros and cons of Magnetic Hard Drives?
Capacity (40GB-2TB), Internal speed (3GB/sec), external (480MB/sec), portable external drives + fixed internal drives, can write to disks countless times but external drives can crash as they are not meant to be moved when spinning. Back-up + archivi
59 of 81
2.1.2(t/u) What are the advantages and disadvantages of Optical devices?
Slow (16MB/sec for DVD), device will fail is surface is scratched + not reliable enough for long-term storage but is portable + has a capacity (CD 700MB- DVD 4.7GB). Mainly used for software distribution + updates.
60 of 81
2.1.2(t/u) What are the advantages and disadvantages of Flash memory?
High speed (480MB/sec), small + portable, durable as there are no moving parts (but case can break if dropped), reliable (but care needs to be taken when disconnecting USB from the connection) + small capacity (250MB – 64GB).
61 of 81
2.1.2(t/u) What are the advantages and disadvantages of Solid State Drives?
Typical Capacity (128 – 512 GB), High speeds (6GB/sec), durable (no moving parts so disk crash is avoided), most reliable of hard drives but isn’t portable.
62 of 81
What is a database? Give examples.
Persistent organised store of data that is used on a computer system i.e. booking systems,product details, price lists, customer details + production of invoices.
63 of 81
What is a database field, table and record?
Field: structure used to contain a single item of data. Record: Collection of fields/single row in a table. Table: collections of records in a table.
64 of 81
How can data handling software be used (i.e. spreadsheet/relational db)?
Sometimes has wizards to help create a commonly used db structure. Data maintenance features: editing/deleting records + adding new records + simple queries used to retrieve specific data from a table or use criteria to filter records to those you wa
65 of 81
What is data redundancy and data integrity?
Redundancy: where data is repeated unnecessarily in a database – time consuming + waste of storage space. Integrity: correctness of data in a database.
66 of 81
What is the Database Management software application designed to do?
Designed to interact with database users, interact with other software applications & capture, extract + analyse data. I.e. Oracle, MS Access + MySQL.
67 of 81
What is Program-Data independence in a DBMS (Database Management Software Application)?
Data is separated from applications that access it so programs work independently of data. Advantage: db admins can modify the software tools that control the db but the db will remain unchanged by these programs.
68 of 81
What is a relational database?
Where data is contained in more than one table –tables joined by linking primary key in 1 table to a foreign key in another.
69 of 81
What is a foreign key and a primary key
The foreign key is a field in a table which can be linked to the primary key of another table to form a relationship while a primary key is a unique identifier (i.e. code number) that can be used to identify each record in a database table.
70 of 81
The most common type of relationship defined in a RDB is one to many. Give examples.
One doctor can have many patients, one student can be enrolled on many courses, one customer can purchase many products.
71 of 81
How can we minimise data redundancy in databases so that less storage space is needed?
Linking data tables can reduce the duplication of data, making it simpler to keep information up to date + increasing the accuracy + consistency of data. i.e. enter customer details only once, link details table with sales, create query for both tabl
72 of 81
What are tables and modules in databases?
Where records of information are stored in a database + created in code to add extra functionality to a database.
73 of 81
What are data entry forms?
Form linked directly to the customer details table + so can be used for data entry or for editing table data – easier viewing as the navigation controls can be used to go through the records; only 1 shown at a time, more spread out + easier to read.
74 of 81
What is a switchboard manager?
Uses a wizard approach to create a main menu or switchboard to navigate and operate a database. Main menus can also be created by adding command buttons to a blank form (used aid navigation through system).
75 of 81
Why are queries used in databases?
To extract info from tables. In some cases, queries are complex + are based on several database tables that are linked together using relationships. By using a reusable query.
76 of 81
What are select and parameter queries?
Select query: most commonly used query where the criteria is fixed + is specified at design time. Parameter query: query that is reusable since it requests the criteria to be input before the query runs.
77 of 81
Why is it necessary to create reports for outputting data that is extracted from the database?
As they’re used to summarise and present the data that is in the tables. Each report can be formatted to present the information in the most readable way possible for display on screen or printed output.
78 of 81
What the pros and cons of using reports in databases?
Time consuming to design but are an efficient method of communication i.e. used by large organisations to provide monthly statements for their customers.
79 of 81
2.1.5 (i) What are validation checks?
Automatic checks made by a computer to ensure that any data entered into the computer is valid and sensible (but there’s guarantee that the data has been entered correctly, only that it’s in a correct format).
80 of 81
2.1.5 (i) Give examples of validation checks.
Input masks (commonly used to control the data entry into a field), presence check (field hasn’t been left blank), range check (value entered falls within particular range) + List check (input from predetermined set of options ensuring only valid dat
81 of 81

Other cards in this set

Card 2

Front

2.1.1(b)How are computers used in the home to automatically control various systems and reduce workload?

Back

By using embedded systems (where a comp processor is integrated into a device for automatic control purposes) i.e. washing machines, central heating control, burglar alarm, dishwashers etc.

Card 3

Front

2.1.1(b)How are computer systems used in commerce and business?

Back

Preview of the front of card 3

Card 4

Front

2.1.1(b)How are computer systems used in medical systems?

Back

Preview of the front of card 4

Card 5

Front

2.1.1(b)Computers are used in embedded systems, home entertainment + communications, commerce + business and medical systems. Where are computer systems also used in the modern world?

Back

Preview of the front of card 5
View more cards

Comments

No comments have yet been made

Similar Computing resources:

See all Computing resources »See all Computer systems resources »