purple.blue27
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(1) Explain three functions of protocols in controlling how data is sent across the network

(2) Why is an embedded system also called a real time system?

(3) Explain why low-level language is used for embedded systems

(4) Explain how an operating system is used to manage use of virtual memory

(5) Explain why a desktop computer would have both magnetic hard disc drive and solid state rive than just having a solid-state drive

(6) Why is an IP address needed to access the internet

People please help
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pereira325
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Why do you not google this.

Question 1 is a revision question soz. The answer is probably in your notes or your revision guide or your textbook.
2 and 3 idk.
4. Well virtual memory is from the hard disk which the OS keeps as spare to act as RAM so the OS has to balance out memory allocation and whatever.
5.If you like computers you should kinda know this already... storage: Hard drives offer a lot more at a cheaper datarice ratio. Solid state drives allow much faster data transfer/access speeds to HDD's and are more reliable (no moving parts).
6. Well think what an ip address does
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Rk13
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2. As it has a faster run time and is more efficient. embedded systems are not too complex so low level languages are fine for them
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purple.blue27
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(Original post by pereira325)
Why do you not google this.

Question 1 is a revision question soz. The answer is probably in your notes or your revision guide or your textbook.
2 and 3 idk.
4. Well virtual memory is from the hard disk which the OS keeps as spare to act as RAM so the OS has to balance out memory allocation and whatever.
5.If you like computers you should kinda know this already... storage: Hard drives offer a lot more at a cheaper datarice ratio. Solid state drives allow much faster data transfer/access speeds to HDD's and are more reliable (no moving parts).
6. Well think what an ip address does
I didn't google because I thought people on tsr will be able to explain easier
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gcsestudent105
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What exam board r u doing?
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winterscoming
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(Original post by purple.blue27)
(2) Why is an embedded system also called a real time system?
Technically, you can have embedded systems which aren't real-time systems, although admittedly that's pretty rare.

"Embedded" refers to a programmable device built into some other larger electronic system - e.g. a programmable microcontroller in a Washing machine which controls the motor, valves, wash cycles, etc.

"Real time" means that the software running on the programmable device must respond or take action almost immediately whenever something happens, because those things are happening in real-time. E.g. if a washing machine reaches a dangerous temperature, its embedded microcontroller needs to quickly cut out the machine to avoid burning out the motor - it might only have a fraction of a second to react to avoid damaging the machine or starting a fire.

So in most cases, if embedded systems weren't real-time, its responses would be too late to properly deal with any events it might notice from its sensors.

(Original post by purple.blue27)
(3) Explain why low-level language is used for embedded systems
Again, you can have embedded systems running software written in a high-level language, but it's not so common. The kinds of programmable devices used in these systems often have extremely limited amounts of memory where every byte and CPU clock cycle counts - furthermore the programs themselves are usually stored on "EEPROM" chips (Similar to the kinds of chips found on a USB stick. Many embedded systems don't have hard disks) - The EEPROM chips used on these controllers are typically limited in space.

High-level languages are often slightly wasteful of CPU, Memory and Storage. Apps using those languages are usually designed to run on modern, powerful devices like smartphones, desktop PCs and servers. These devices can afford to waste a few megabytes of memory or a few million CPU cycles here and there. Nobody is going to care whether a Smartphone app uses 256KB or memory or 10MB of memory - high-level languages are designed with the assumption that there's plenty of spare CPU/Memory capacity.

On the other hand, programmable microcontrollers might have a CPU which is only capable of running at 10MHz, and may only have 64KB of memory. When every CPU cycle counts, and when every byte in memory is valuable, optimisation is important, and it's a lot easier to write highly optimised code in a low-level language like C, or even using assembly language. Also, the compiled size of the executable itself needs to fit on the EEPROM chip, so if that chip is also only 256KB in size, then that's the physical maximum size of your compiled program.

There's no technical reason why a washing machine couldn't use run on something similar to a smartphone, but there'd be a lot of unused and wasted CPU cycles and memory. Instead of the manufacturer paying maybe £5 for the programmable microcontroller, it'd cost £100 and that would either increase the cost of the appliance, or it would eat into their profit (e.g. if they're selling 100,000 machines, then that's a lot of lost profit.)
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purple.blue27
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(Original post by gcsestudent105)
What exam board r u doing?
OCR
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Deuterium1
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Stackoverflow and Teach ICT are you're best friends with anything computing related
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