Index Register is used to change addresses. Through changing the data in Index Register, user can make an object to read and write
different addresses without changing its own address settings. This is the technology used in most terminals when displaying multiple fields in a single image.
Example:
■ Word: Set read address
to LW-20, use Index Register 1 , and the value in Index Register 1 set to 10.
The system will read the value in LW-30.
We use this technology on almost any terminal application, could you implement it too?