Permanent Memory Chip
The permanent type of memory chip is known as the Read-Only Memory (ROM) chip. This type of chip has a set of instructions or programs in it for the computer to use. The contents of a ROM chip are put there permanently and stay there whether the computer is switched on or off. Generally, ROM chips are used to carry instructions for the computer to start up when it is switched on, and it is not obvious to the user that the ROM chips are inside the computer. The instructions include the process of telling the computer to look for an operating system: this is part of what is known as the ‘bootstrap’ program, thus ‘booting up’.
ROM chips often look like this:
There are variations on the ROM chip. Some of them can be reprogrammed and are known as Erasable Programmable Read-Only Memory (EPROM). They can be identified by a little plastic window in the top of the chip.