Perfect Computer Notes

Topic:  What is ROM Explain Different Types of ROM ROM ROM stands for Read Only Memory , because its contents can be read and used only and we cannot change or delete its contents. It is a non volatile memory. Its retains its contents even after switching off the computer. Therefore, ROM does not require electricity to retain its contents. ROM is a permanent memory. The instructions in ROM are written at the time of manufacturing by the manufacturer.   Importance of ROM in Computer System 1. One important reason a computer needs ROM is that instructions stored in ROM (called ROM BIOS - Basic Input/Output System)execute on start-up of computer and guide the computer what to do. They make the computer ready for work. 2. ROM contains a set of start-up instructions to check that memory is functioning well and check for other hardware devices. 3. These instructions also check for an operating system and load its necessary part into RAM, so that a user interface for exa...