The 4 Segmented Registers in Intel 80286

The Intel 80286 is a microprocessor chip that was introduced in 1982. It was the successor to the Intel 8086 and 8088 processors and was used in IBM PC/AT and other compatible computers. The 80286 had several new features and improvements over its predecessors, including the introduction of segmented memory architecture.

One of the key features of the segmented memory architecture is the use of segmented registers. These registers are used to store the segment addresses of various memory segments in the system. The 80286 has four segmented registers that are used to address different types of memory segments. They are:

1. AS (Application Segment) - This register is used to store the segment address of the current application code segment.

2. BS (Backward Segment) - This register is used to store the segment address of a data segment that is located below the current data segment.

3. CS (Code Segment) - This register is used to store the segment address of the current code segment.

4. DS (Data Segment) - This register is used to store the segment address of the current data segment.

The use of segmented registers allows the 80286 to address up to 16MB of memory, which was a significant increase over the 1MB addressable by the 8086 and 8088 processors. It also allowed for more efficient memory management and protection.

In conclusion, the four segmented registers in Intel 80286 are AS, BS, CS, and DS. These registers are used to store the segment addresses of various memory segments in the system and allow for efficient memory management and protection.