A Dummies Guide to computer memory

Differences between ROM and RAM ROMRAM Non volatileVolatile Used to boot up the computerUsed when the computer is running Located on the motherboardGoes into a socket on the motherboard It cannot be change by the userIt is changed every time the PC is turned on

ROM (Read Only Memory)  ROM stores the data that the computer uses to boot up.  It is saves its memory when the computer is turned off which means it is non volatile.  A ROM chip is located on the motherboard.  It cannot be changed by the user as it is ‘read only’  ROM stores the data that the computer uses to boot up.  It is saves its memory when the computer is turned off which means it is non volatile.  A ROM chip is located on the motherboard.  It cannot be changed by the user as it is ‘read only’

RAM (Random Access Memory)  RAM is volatile memory which means that when the power is turned it loses all the memory.  It is connected to the mother board by a vertical socket.  RAM is needed to have more than one window open at the same time and to switch between them.  When the RAM is full the computer will start to run slow, it will try to use the Hardrive as RAM which can lead to thrashing of the Hardrive.  RAM is volatile memory which means that when the power is turned it loses all the memory.  It is connected to the mother board by a vertical socket.  RAM is needed to have more than one window open at the same time and to switch between them.  When the RAM is full the computer will start to run slow, it will try to use the Hardrive as RAM which can lead to thrashing of the Hardrive.

How does the size of RAM affect the PC  If you have lots of windows open and the RAM isn’t very big then the computer has to use the Hardrive as the ram which can lead to thrashed Hardrive and a slow computer  If it is small you cannot have many programs running at the same time so you cannot be doing homework while on the internet and other applications all at the same time.  If you have lots of windows open and the RAM isn’t very big then the computer has to use the Hardrive as the ram which can lead to thrashed Hardrive and a slow computer  If it is small you cannot have many programs running at the same time so you cannot be doing homework while on the internet and other applications all at the same time.

Virtual memory  Virtual memory is when the Ram is full and some of the hard disc has to be used instead  It is needed when you have a lot of windows open and running  Virtual memory is very slow compared to ‘real’ RAM and can damage your hard disc this is called the thrashing of the hardrive  Virtual memory is when the Ram is full and some of the hard disc has to be used instead  It is needed when you have a lot of windows open and running  Virtual memory is very slow compared to ‘real’ RAM and can damage your hard disc this is called the thrashing of the hardrive

SRAM and DRAM  There are two main types of RAM, Static RAM (SRAM)and Dynamic RAM (DRAM)  The most common type is DRAM as it is a lot cheaper than SRAM although it is slower  The main disadvantage to DERAM is that it has to be refreshed by a signal with every clock cycle in order to retain its data  If the refresh signal is lost then data will disappear even though the chips are still powered up  There are two main types of RAM, Static RAM (SRAM)and Dynamic RAM (DRAM)  The most common type is DRAM as it is a lot cheaper than SRAM although it is slower  The main disadvantage to DERAM is that it has to be refreshed by a signal with every clock cycle in order to retain its data  If the refresh signal is lost then data will disappear even though the chips are still powered up

Flash memory  Flash memory is a way of storing 1s and 0s  It is rewritten by using a ‘flash’ of electricity by trapping electrons behind gates  Most modern USB sticks are flash memory  Flash memory is a way of storing 1s and 0s  It is rewritten by using a ‘flash’ of electricity by trapping electrons behind gates  Most modern USB sticks are flash memory