Index registers are circuits in a computer processor that store and output instruction-changing codes. They hold address information that is used to locate data or instructions in memory. Index registers were first introduced in 1949 in the Manchester Mark 1 computer and became standard in most computers during the 1950s-1960s. Modern computers typically contain multiple index registers, sometimes over a dozen, to improve performance by allowing faster access to memory locations compared to using main system memory alone.

1. Index Registers
Presented By:
Reg # CS_08

2. What are Registers?
A register is a data-holding place in a
computer processor. A register can hold
an instruction, a storage address, or any
kind of data.
The effective address of an entity in a
computer running multiple programs
comprises the base, index, and relative
addresses, all stored in the index
register, and any of which can be
modified by the index register before the
entity is acted upon (for example, an
instruction is carried out).

3. Index Registers
An index register is a circuit that
receives, stores, and
outputs instruction-changing codes in
a computer. This circuit is also called
an address register or a register of
modifications.

4. History of Index Registers
Index registers, commonly known as a
B-line in early British computers, were
first used in the British Manchester Mark
1 computer, in 1949. In general, index
registers became a standard part of
computers during the technology's
second generation, roughly 1954–1966.
Most machines in the IBM
700/7000 mainframe series had them,
starting with the IBM 704 in 1954, though
they were optional on some smaller
machines such as the IBM 650 and IBM
1401.

6. Why do we use more Index
Registers?
A typical computer contains several
index registers, sometimes more than
a dozen. Index registers operate much
faster than primary storage (main
memory), although part of the primary
storage may be assigned to the index
register if needed. The index register
improves computer performance by
speeding up simple operation