2.2 Digital Systems Flashcards
Operating Systems Manage Resources
- managing peripherals such as input and output devices
- manages printing using spooling
- manages backing store
- file compression
- disk defragmentation
- manages memory RAM
- manages processes
- manages security
GUI
Windows icon menu pointer
Advantages
- easy to navigate
- it’s intuitive
- WIMP
Disadvantages
- requires lots of memory = windows to load
- very slow
Touch Sensitive
Smart phones
Advantages
- very intuitive
- easy hand to eye coordination
- better than mouse
Disadvantage
- can get dirty
- unhygienic
- difficult to touch small items
Command Line
For professionals (network management)
Advantages
- quick to type commands
- little memory and processing power
Disadvantages
- large number of commands needed
- not suitable for a novice
Menu Driven Interface
Uses work through a series of menus to execute routines
Biometrics
Body measurements and calculations related to human characteristics
Voice Driven Interface
Recognition and interpretation of speed patterns
Application Software
Is where things come right off the shelf to fulfil a specific purpose - Microsoft word or data managing
Bespoke Software
Software written to perform a task for an individual or a company - stock or custom stuff
Advantage
- organisation controls timings and speed development
Disadvantage
- initial cost is high compared to off the shelf
Process Control
Software that manages a process feeding back information from a variety of sources to control input and output
Antivirus Software
Scheduled virus software that scans and blocks off harmful viruses
Quarantine = antivirus software moves the infected file to a safe part of the system ensuring no other files get infected
Clean = antivirus software removes the infection from the file instead of deleting it just in case the user needs the file
Deleting = antivirus software deletes the file from the system completely
Task Scheduling
A part of a operating system which is used to run commands can be set by the user to run automatically based on circumstances - sending an email or making a backup
Full Backup
Every single folder and file on a device or network is copied and saved
Incremental Backup
Copies all files that have been created or changed since the last incremental backup
Differential Backup
Copies all files that have been created or changed since the last full backup copy
Grandfather Backup
A full machine backup performed monthly and held of site
Father Backup
A full backup done on a weekly basis and held locally
Son Backup
Daily differential backup
USB Flash Drive
This media uses flash memory and is portable and lightweight
Lower memory capacity that other backup media and can be used to transfer data from device to device. Suitable as temporary backup
External Hard Drive
Hard drives store large amounts of data. They are portable, cheap and quite efficient
Solid State Media
Uses flash memory to store data. Can hold large amounts of data and add more robust as they have no moving parts. Can be very expensive, has an upper limit to how many times it can be read or written to
Cloud Storage
Storing data and files at a remote location using the internet. When data is sent to be stored on the cloud, it is sent to a server that is hosted by an external company
Disaster Recovery Plan
In place in case of system failure from a power cut to natural disaster
Cloud Computing
The on-demand availability of computer system resources especially storage and computing power - AWS
Advantage
- lower set up costs and compatibility issues reduced
Disadvantage
- cloud versions of software is not always the most up to date and an internet connection is required to create, edit, save and retrieve files
Software as a Service
Most used service, all applications are run through the web browser meaning clients don’t need to download anything - Google docs
Platform as a Service
The cloud provider has more control managing the hardware potion, the operating system and other elements clients manage the application and data portion - Google app engine
Infrastructure as a Service
The cloud provider manages the hardware portion such as servers, storage and networking, clients will manage software portion - applications + operating system
Cloud Storage
Computer data storage available on demand and remotely - google drive
Advantage
- very reliable and cost effective platform - good cloud
System Development Cycle
Investigation
Analysis
Design
Implementation
Maintenance
Evaluation
System Investigation
System analyst would investigate the current existing system and create a feasibility report looking at
- Detention of scope of the current system
- Existing hardware and software
- Problems with existing system
- User requirements of the system
- Cost and benefits of introducing a new system
System Analysis
- understand what data flow diagram is and be able to interpret one
- understand what a decision table is
- understand what a data dictionary is
System Design
- hardware
- software
- network
- staff issues
- security procedures
System Implementation
- installing the hardware and software
- changeover methods - parallel, direct, pilot and phased method
System Maintenance
- user guides
- technical manuals
- error checking
System Evolution
Evaluating a new system - to determine weather the new system meets the initial requirements and needs of the company. How the software can now further evolve is also looked at during this stage
