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Hardwired and Software Controlled Systems

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A2:
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Hardwired or Software Controlled

Hardware

Hardware is the physical parts of the computing device. If you drop it or spill a drink into it, it will break. If you drop it onto your foot, you'll curse and swear because it's often heavy or fragile. A phone is hardware.

Software

This is the information stored on disk or flash memory pen drive. Software must be backed up or it will eventually get lost. You can send software to another person using email or by file download. The operating system, applications, music, photos and videos stored on your phone are software.

Hardware or Software

Almost all hardware can be built using software instead.
Almost all software can be built using hardware instead.
So which is better?

Here are some factors that need to be considered when deciding whether to use a hard wired control system or a programmable one.
	Hard Wired	Programmed
COST	Expensive - needs custom designed circuitry.	Cheap - uses a general purpose programmable chips.
FUNCTIONALITY	Inflexible - every control system needs a different hard wired solution.	Flexible - a single design of processor can be used in many different control systems.
UPDATING / MODIFYING	Can't be modified. This is OK for simple systems that never need to be altered.	Can be altered by re-programming.
RE-PROGRAMMING	Not Possible.	Can be re-programmed. This is useful for control devices that may need to be upgraded or modified after maintenance work has been carried out. A new model of an appliance might have a slightly different control program but the same controller.
STAFF EXPERTISE	No need for a programmer. Hardware specialists are needed.	Need a trained programmer to set up the control system. Less need for hardware experts.
RELIABILITY	Mechanical control systems fail because of wear and tear on the moving parts and corrosion.	More reliable because there are no moving parts. The electronics can be embedded in plastic resin to prevent corrosion.
TESTING	Hardware testing is more complex and expensive than software testing.	Software testing is cheaper that hardware testing for all but the most complex software projects.

Social and Economic Benefits

Software controlled devices are very common and useful in every-day life.
Mobile phones keep people in contact, especially during emergencies.
Before mobile phones, you'd need to walk to a phone box to report a fire or accident.
Embedded software controlled devices cost less and are easier to use.
Text displays provide more information for the user.
Audio outputs help visually impaired people.
They improve the environment ...
- Eco programs for washing machines and dish washers.
- Run the appliance at night using green electricity.
- Reduce petrol or diesel pollution by electronically managing the engine.
Devices connected to computer networks allow people to ...
- Buy rail or air tickets using machines of the Internet.
- Find out when the next train or bus is due and if it's been delayed.

This list could go on and on ...

Hardwired and Software Controlled Systems

Hardware

Software

Hardware or Software

Hard Wired

Programmed

Social and Economic Benefits