Many components that go into computer systems are toxic and dangerous to the environment if released or disposed of inappropriately.
Heavy metals are used in batteries and circuits and these can pollute groundwater or kill animals if left exposed on landfill. Large quantities of plastics are used in systems, which take a long time to break down, some of the plastic will eventually break down into toxins as it degrades.

Parallel

• sending data from a computer to a printer
•  internal data transfer (buses)

Serial

• connect a computer to a modem

Uses transistors( resistors and capacitors) . It can be implemented by the use of NAND or NOR gates. Data is stored on the chip as a charge

b) Study the following pseudocode and answer the questions that follow.

1. Start

2. Get Value1 and Value2

3. If Value1> Value2 Then

4. Maximum = Value1

5. Else If Value1< Value2 Then

6. Maximum = Value2

7. Else Go to 9

8. Display Maximum

9. Stop

i) State the purpose of the pseudocode                                                                                  [1]

To compare two values and output the greater of the two

ii) Draw a flowchart equivalent to the pseudocode.                                                                     [8]

• TCP/IP

• Power surge/loss (damages hardware)
•  Use a UPS
• Water can be spilt on the device
• Don’t have water near the device
• Keep the device in a waterproof box when not is use
• Fire can destroy the device
• Use electrics safety
• Keep the device in a fireproof box when not in use
• Data is accidentally deleted
•  Add verification method for data deletion
•  Set access levels for data to limit who can delete the data
• Incorrect use of storage device
• Making sure the device is ejected before removing
•  Physical damage to hardware // hardware failure
•  Correct care and maintenance of hardware
•  Software failure 
• Making sure it is always up to date // enable automatic updates

(i) Unexpectedly halts the program. Run time (execution)

(ii) The program produces the wrong output.  Logical
 (b) Another error can result from incorrectly using the rules or grammar of the programming language.

(i) Name this error. Syntax

(ii) State when this error is detected.

Syntax error is detected during translation into executable code / attempted to run but fails

 A single executable file is produced 

The executable program is portable between machines

The program source code is not available

Code can be optimised/made more efficient 

Entire source code file is converted at once

No special environment is needed to execute the code 

It creates object/machine code

Error report is provided at the end of the compilation

• By setting the validation rule for the input controls on the property sheet in design view
• By use of VBA to restrict user inputs for a given control on a form
• By use of queries to restrict options available for the user in a combo box or listbox
• Setting correct data types for the fields in table the design
• Enforcing referential integrity in database relationships
• Use of input mask for the controls on the property sheeet in design view

• Access Controls: Authentication of users in order to access files
• Performing regular patches of updates
• creating secure accounts with required privileges
• scrutinizes all incoming and outgoing packets of data through a firewall
• encryption of data, during transmission
• Log files to detect any breach

• A computer is an electronic device that operates (works) under the control of programs stored in its own memory unit
• An electronic device that accepts data, as input and transforms it under the influence of a set of special instructions called programs, to produce the desired output (referred to as information)

• she had actually described verification
• data could be incorrect, therefore same incorrect data typed in twice
• accept description of validation process e.g. range check

• Repairing files
• Compression
• Defragmentation
• Back up
• Anti-virus / anti-spyware / anti-malware
• Firewall
• Managing application updates
• Format disks/drives
• System analysis tools

Incremental:

• Only the changes need to be backed up
• The software/OS/settings are unlikely to have changed between backups
• Small number of files likely to be used/edited between backups
• Take less time to backup
• Each backup will take less memory space to store

Full:

• Backup all the data/files and software
• It might not take a significant time to back up entire system
• He might only have a small number of files to be backed up each time
• Safer as have more past versions to revert to
• User may have changed settings on computer
• Faster to restore the backup
• Needs to do a full before he can do an incremental

The user is not allowed to access the source code so, they cannot tailor the software to their needs and  they cannot fix any bugs in it

The software is still covered by copyright

The user must get the owner’s permission to do anything beyond using it

emails: – fast delivery of messages (to recipient’s mail box)
– able to send attachments
– can store messages for later use
– auto-translation no language problems
– can open email at a convenient time
video conferencing/calling/chat:
– removes need to travel (saves time and money)
– allows face to face discussions
– works in real time (only allow once)
VoIP: – much cheaper than normal international calls
– direct communication between people
– works in real time (only allow once)
chat rooms/instant messaging:
– instantaneous reply
– anyone can join in
social networking:
– can ensure only your “friends” are in communication
– usually free to join and use
– talk to (multiple) friends at the same time

• Computer systems use binary/ones and zeros/voltage on or off;
• Sound is analogue/continuous;
• Computers use digital data/discrete values

• Because data is recorded to the disks once but can be accessed many times without changing the content
• once data is written to the disk, it becomes read-only and cannot be altered or erased.

A formatting or editing operation that is applied to a block of text after selecting. The block of text can be a paragraph, line, word, page or the whole document. It is much easier to apply editing or formatting to a block of text than to apply it to every single character