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1.1,1.2 and 1.3 (1.2 (Properties of flash memory (not easily damaged by…
1.1,1.2 and 1.3
1.2
RAM: Fast, expensive and volatile. Primary storage
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ROM: Fast access, expensive, non-volatile.
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ROM is often made from flash memory. This means that it's contents cannot be changed easily. This means that the ROM only stores small programs that boots or starts up the computer.
Common examples of flash memory are SSD, SD cards and ROM.
Flash storage provides high capacity for their physical size, which is useful in small devices.
Flash memory is usually based on a technology called Electrically Erasable Programmable Read-Only Memory (EEPROM). EEPROM can be used to create many flash memory devices:
SD cards are used to extend the capacity of devices such as cameras and tablets. They provide high capacity for their physical size. This is useful in these smaller devices.
The Read-Only Memory chips on board modern Central Processing Units (CPUs) are made from EEPROM. This provides the software needed for the computer to start.
SSDs are often used in home computers because of their performance. SSDs are a form of re-writable flash storage.
Flash memory: non volatile, short lifespan, fast access, robust. Solid state drives are a common alternative to hard disk drives because of their high performance.
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Virtual memory
Memory can be split into sections called pages. moves pages between ram and secondary storage when ram is full. however slower because secondary storage is further away from cpu than main memory
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Virtual Memory allows us to access more memory than we have by setting aside some secondary storage space to act as extra memory.
1.1
Computer systems are made of hardware and software which work together. Hardware are the physical components of the computer, such as:
Primary storage is the memory in which the computer can store the data or instructions that are currently in use.
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I/O devices allow users to input data into the computer, or receive a data output from the computer, suck as keyboards, mice and monitors.
A processor is a special component that processes data and instructions to control other components within the computer. The 2 main types are GPUs and CPUs
Secondary storage is the memory in which the computer can store the data or instructions which are NOT currently in use. And not all computer systems use it. The main types are HDD, SSD, CD and USB.
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1.3
Capacity
To calculate the amount of data that can be stored within a certain capacity, you need to know three things:
Units
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The capacity of a device is how much data it can store. It is important to know the units of capacity so that we can compare the capacity of different devices.
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Solid state storage
Solid state media has a lot of benefits, but it isn't the best media in all scenarios.
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how it works
Solid state storage is an increasingly popular alternative to other storage media. It is often also referred to as flash storage or flash memory.
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Magnetic storage
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data can be stored anywhere on disk, so location must be found first. accesses data while platter spins
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Magnetic tape used to be used to distribute content. Now, the main purpose of magnetic tape is to make backups.
stores os, apps and user data
