Ram and Rom
MEMORY
PCs have quite a bit of memory of different kinds. Let’s take a look at some general concepts that will help us understand what we are talking about when we say “memory.”
Storage One of the things we expect our PCs to do is to store information. This information can be our data files, it can be our application software, or our operating system. If this information were not stored in the PC itself, we would have to re-install it every time we turned on the PC, and then it would have to be stored or kept somewhere while it was being used, as well. So right here we can see that there are two kinds of storage – short-term or temporary, and long-term or permanent. Permanent storage is the kind where the information will be accessible the next time we turn on the PC – that is, the information does not disappear when the power is off. Permanent storage is more properly known as secondary storage. The kind of devices that are secondary storage devices are those that maintain data when the power is off: hard drives, floppy disks, CD and DVDs, ZIP disks and so on. Temporary storage, on the other hand, is where data, applications or programs reside while the system is using them. This kind of storage is called primary storage. RAM is primary storage. Information in primary storage is volatile – it is lost when the power is off. It’s important to remember that the CPU can only access something that is in primary storage. The CPU has no direct connection with secondary storage devices. If it needs to work with a particular piece of data, that data must be moved from secondary storage (your hard drive) into primary storage (RAM). Therefore, the more RAM a PC has, the more information can be readily available to the CPU and the faster the data can be processed. PCs have a great deal of secondary storage and much less primary storage. Secondary storage is where all information is kept on a permanent basis, until deleted, and primary storage only holds information
PCs have quite a bit of memory of different kinds. Let’s take a look at some general concepts that will help us understand what we are talking about when we say “memory.”
Storage One of the things we expect our PCs to do is to store information. This information can be our data files, it can be our application software, or our operating system. If this information were not stored in the PC itself, we would have to re-install it every time we turned on the PC, and then it would have to be stored or kept somewhere while it was being used, as well. So right here we can see that there are two kinds of storage – short-term or temporary, and long-term or permanent. Permanent storage is the kind where the information will be accessible the next time we turn on the PC – that is, the information does not disappear when the power is off. Permanent storage is more properly known as secondary storage. The kind of devices that are secondary storage devices are those that maintain data when the power is off: hard drives, floppy disks, CD and DVDs, ZIP disks and so on. Temporary storage, on the other hand, is where data, applications or programs reside while the system is using them. This kind of storage is called primary storage. RAM is primary storage. Information in primary storage is volatile – it is lost when the power is off. It’s important to remember that the CPU can only access something that is in primary storage. The CPU has no direct connection with secondary storage devices. If it needs to work with a particular piece of data, that data must be moved from secondary storage (your hard drive) into primary storage (RAM). Therefore, the more RAM a PC has, the more information can be readily available to the CPU and the faster the data can be processed. PCs have a great deal of secondary storage and much less primary storage. Secondary storage is where all information is kept on a permanent basis, until deleted, and primary storage only holds information