Week 03 Flashcards
Define software
A series of detailed instructions
(programs) that control the computer operation
– Computer devices only as good as their software
Define the difference between systems software and applications software
Systems software manages and controls the
operation of the computer system for the user
* Application software provides functionality of
interest to the user
How is software affected by moores law with hardware
Constantly hardware is advancing, hardware will determine a computers potential wheras the software determines the actual usability of the computer. Software needs to evolve to take advantage of hardware - otherwise we face incompatibilities
Why was QWERTY Keyboard made that way?
For typewriter operation - mechanically it made sense as two neighbouring arms would not come up at the same time Early typewriters jammed and so the keyboard was designed in part to slow down
typing
Can we change the QWERTY keybaord? How and why don’t people
Can change by software but we don’t because people are used to the typing
What are two reasons for drag in updating software?
- People are used to way things are used
- People have to program these changes and not alot of people can program. There tends to be a backlog in updating software
Explain operating systems with example
Allocating and managing system resources
Scheduling resources and monitoring the computer
Basically housekeeping tasks on computer
- Controlling access to storage devices e.g. USB key
– Co-ordinating and controlling peripherals
– Allowing users to input data and instructions ex: Keyboard, mouse
Explain a virtual machine
A virtual machine involves simulating a
complete computer system in software.
– e.g. running Windows programs on an Apple OS
Explain utility programs with example
a range of tools that support the operation and
management of a computer system
* monitor system performance
* provide security controls
ex: virus detection
Explain Development programs with example
Computer software (system and application) is
written in programming languages to carry out
specific information processing tasks. Most people cannot sue these programs.
– Languages like Java, C++, BASIC, Python
Define Application specific software
supports specific business processes or functions
* HR, Finance, Operations, Marketing
People use computers for different applications and so need different operations in place.
Why do we generally use general purpose applications? give an example
Usually use off the shelf programs as not many people can program customised ones. ex: excel
Give an example of Fully customised applications, customised general software and customised sectoral software
Fully Customised applications
– Written from scratch
Customised general software
– Macros in Excel
Customised sectoral software
– R programs
What are four challenges in Building software? - explain
Systems analysis – Software requires precise description and people find it difficult to provide this. Level of detail is hard for humans to provide.
* Programming- Attention to detail required and skills in short supply
* Testing - for edge cases especially, may need to devise appropriate test data
* Implementation – Good software can be badly implemented e.g. inadequate training, bad data
What was the first spreadsheet and why was it created?
Designed by a business school student to do his assignments. Visicalc was a brilliant design in 1970s
Explain the permissive nature of spreadsheets while contrasting flexibility to supportive
Spreadsheets are permissive, they allow you do many different types of work this ensures flexibility. Flexibility is counter to support, so spreadsheets do not stop you
making errors, which means the system builder has to be both careful and skilled
Why are spreadsheets used a modelling tool, what might be things to look out for?
– easy for end user quick and dirty development
– increasing macro capability
– formulas entered independently – little control over modelling process
- Data can be interchanged with specialised software and supplementary tools
Give 2 examples of badly designed spreadsheets giving the wrong answer
16000 UK Covid-19 test results lost for a week
24% of Enron spreadsheets with formulas,
contained errors, contributing to corporate failure
Describe spreadsheet good practices
- Design for longevity.
– Focus on the required outputs.
– Separate inputs, workings and outputs
– Be consistent in structure, use of formulae.
– Keep formulae short and simple.
– Never embed in a formula anything that might
change or need to be changed.
– Perform calculations once and then refer back to
that calculation.
– Avoid using advanced features where simpler
features could achieve the same result.
How to test spreadsheets
Check multiple times - get other people also to check
anticipate the answer you should get before you calculate in your checks
Break your spreadsheet deliberately if you can - be aware of what can break it.
test boundary inputs
Why apple over PC?
Apple provides an integrated environment where they build the hardware and
software and they ensure that it all works together.
Windows (laptops) and Android (phones) have more combinations of the
applications and hardware and sometimes this does not work well.
What is BIOS
BIOS, Basic Input/Output System is a small computer program is typically by the CPU to perform start-up procedures and load up the operating system
Explain the different steps of opening up spreadsheet data on a turned off computer
Hardware and BIOS at play
Operating system comes online - provided by windows
GUI and environment also - provided by windows
Application is opened - excel
User data - spreadsheet data can be seen
Explain the different steps of opening up spreadsheet data ona turned off phone
Hardware and BIOS at play
Operating system comes online - provided by android
GUI and environment also - provided by android
Application is opened - excel
User data - spreadsheet data can be seen
