6. (A) Differentiate between RAM and ROM. (B) Name three basic buses employed in a computer and explain what each is used for. (C) Draw a basic computer block diagram and briefly explain the function of each part. (D) Describe various types of computers classified on the basis of size, memory, capacity and speed.

A) RAM (Random Access Memory) and ROM (Read-Only Memory) are both types of computer memory, but they serve different functions. RAM is volatile memory that allows the computer to access data quickly, but the data is lost when the computer is turned off. ROM, on the other hand, is non-volatile memory that stores important information such as the BIOS that controls the computer’s startup process. The data in ROM cannot be modified, and it is not lost when the computer is turned off.

B) The three basic buses employed in a computer are:

1. Address Bus – used to transmit memory addresses from the CPU to memory or other devices.
2. Data Bus – used to transmit data between the CPU, memory, and other devices.
3. Control Bus – used to transmit control signals between the CPU and other devices, such as signals for reading and writing data.

C) A basic computer block diagram typically includes the following parts:

1. Input Devices – used to input data into the computer, such as a keyboard, mouse, or scanner.
2. CPU (Central Processing Unit) – the “brain” of the computer that processes data.
3. Memory – stores data temporarily (RAM) or permanently (ROM).
4. Output Devices – used to output data from the computer, such as a monitor, printer, or speakers.
5. Storage Devices – used to store data permanently, such as a hard disk drive or solid-state drive.

D) Computers can be classified based on several factors:

1. Size – can range from small handheld devices to large supercomputers.
2. Memory – can range from a few kilobytes to several terabytes.
3. Capacity – can range from basic word processing to complex scientific simulations.
4. Speed – can range from slow processors for basic tasks to high-speed processors for advanced computing applications.

Types of computers include personal computers (PCs), laptops, tablets, servers, mainframes, and supercomputers.