‫Hello and welcome in in this lecture, we are going to discuss what memory is.
‫So firstly, what is memory?
‫Well, memory is a piece of hardware that allows computers to store information.
‫Random access memory is your computer's main memory programs can read and write information here.
‫Read-Only memory is a form of memory that can only be read from.
‫We will now discuss the differences between the two.
‫So RAM is a writable memory and can be written or read from Rame is only used for temporary storage
‫and all data in rhyme is lost when you power down your computer.
‫So when would you use REM?
‫Well, you would use REM when you write a program that deals with variables.
‫For example, whenever you program in C and you have a program that stores, I don't know, 50 in variable
‫A 50 is actually getting stored in your computer's memory, your computer's ram when you power down
‫your computer, that 50 in RAM is gone forever.
‫Now let's explain read-only memory.
‫Read-Only memory cannot be written to through normal means.
‫Read-Only memory is permanent storage and will maintain its data after power loss.
‫So whenever you shut down your computer, the ROM will always be the exact same when you put it back
‫up.
‫So you generally use Romme when creating programs for embedded devices.
‫For example, the microcontroller in your Ketso that senses when the kettle is getting too hot and needs
‫to turn the power off would have read-only memory.
‫That read-only memory would contain the program that the capsule uses to check the thermostat.
‫Upon turning your cazzo back on that read-only, memory gets executed in your home computer.
‫Your bios is stored on a ROM.
‫We'll discuss more about the bias in another video.
‫But your bias is actually stored on a room and it never changes.
‫It does not matter how many times you turn your computer on and off.
‫The bios will always remain the same because it's stored on read-only memory.
‫This is a picture of a bios rom chip.
‫On a motherboard, another thing you should be aware of is that memory is generally accessed in a linear
‫fashion.
‫For example, you might say from memory address 50.
‫This will then read from memory just 50, you might say, from memory address 62.
‫It will then read from memory address sixty two.
‫The data is stored in order in a linear fashion.
‫However, when accessing memory through the use of your process, please bear in mind the processor
‫has different types of memory schemes.
‫It has segmentation and so on.
‫There's different ways to access memory through your processor.
‫But when talking to memory directly, usually the memory is read in a linear fashion.
‫Please don't worry too much about this stuff because we will discuss more about how the process accesses
‫the memory as the course progresses.