| MEMORY |
| “This machine has all the latest technology. There is a built-in DVD burner, 4-channel sound and 128 megs of RAM. Here let me boot this machine and demonstrate how fast it is. With our current special Computerhouse will double the memory, making a total of 256 megs of super fast RAM”. Boot a machine? What does a machine have to remember, the times tables? Let’s cross over to the computer zone and find the answers. The word BOOT comes from bootstrap. Originally starting a computer meant loading a special deck of cards that told the computer what was attached to it, such as disk drives and printers. For home pc’s this is contained in a special section of ROM called the BIOS. Once all peripheral devices are loaded (the drivers and everything else needed to let the computer know what is available), and then the operating system is started. BIOS is Basic Input Output System. The BIOS is built-in software that determines what a computer can do without accessing programs from a disk. On PCs, the BIOS contains all the required to control the keyboard, display screen, disk drives, serial communications, and a number of miscellaneous functions. The newer machines have what is called flash bios. Same idea, but it can be updated. ROM is Read Only Memory. This is permanent memory used to start up the computer. These are on chips and help the computer process tasks. Some of the boot process instructions are stored here. This is non-volatile memory or memory that is not erased when the power is shut off. RAM is Random Access Memory. This is volatile memory. Whatever is in here goes away when the power is removed. The operating system uses part of this as do programs. Thus when you start your computer, the OS (operating system), loads what it needs and the remainder is used for whatever the user is going to do. When a program is in use, like a word processor, the OS calls for instructions and these come from the hard disk (or cd or disk drive for some applications). The entire program is not loaded but only what is needed at the time and calls for more instructions as needed. RAM is faster than instruction calls to a disk. The program looks ahead and knows that certain instructions will be needed to process incoming data. These are loaded into RAM. The more RAM, the faster work can be processed. Let’s look at a very simple example. Windows 98 (the OS), needs 32 megs of RAM minimum. MS Word needs 10 megs of RAM minimum. (These are not the precise numbers but are used simply as an example). If your computer has only 48 megs of RAM, that leaves only 6 megs to the work you want to do. Of this 6 Megs left, 1 or 2 megs will be used by the video card. |