What is Computer?

A Computer is an electronic and programmable machine. Which accept input information or data that it process according to our instruction and then supplies the output. The IBM PC was introduced in the early 80s and since then has been modified and improved. The modern computers are electronic and digital. The actual machinery, which are wires transistors and circuits.

Computer Architecture

Computer architecture refers to those attributes of a system visible to a programmer, or put another way, those attributes that have a direct impact on the logical execution of a programme. Examples of architectural attributes include the instruction set, the number of bits used to represent various data types (e.g., number, characters), I/O mechanism, and techniques for addressing memory.

General Architecture 8086/8088 Processor:

The architecture has two units:

1) Execution Unit.

2) Bus Interface Unit.

Execution Unit

The execution unit holds:

• 4-General Purpose Registers

• 4-Index Pointer Registers

• Temporary registers or Internal Communication Registers.

• Execution Control Logic

• A.L.U. or Arithmetic Logic Unit.

• Flag Registers.

General Purpose Registers

General Purpose Registers are:

Ax: Accumulator: used to store the result.

Bx: Base Register: used as an instruction pointer.

Cx: Counter Register: used as a counter for specific instruction.

Dx: Data Register: