Section 2

Registers

In this section we will describe the use of the nine addressable storage registers and the manupulating of information in the stack. Also, to illustrate a use of the stack registers we will present a manual solution to a problem of compound interest.

Addressable Registers

Registers R1, R2, . . . , R9 constitute the addressable registers. Their respective contents are referred to as r1, r2, . . . r9. Operations refer to them by number. The registers are typically used to accumulate sums or to store constants or intermediate results. You can store the value of the stack’s X-register in any addressable register, or you can recall the value in any addressable register to the X-register. Additionally, you can store in any register an arithmetic sum, difference, product, or quotient of the contents of the given register and the X-register. For example, if R5 contains 100 and if X contains 70, you can store the difference (100 — 70 = 30) in R5 simply by pressing STO 5.

Storing and Recalling Data

To store a number appearing in the display (whether the result of a calculation or keystroke entry):
1. Press STO.
2. Press a number key 1 through 9 to specify in which of the nine registers the number is to be stored.
If the selected storage register already has a number in it, the old number will be overwritten by the new one. The value in X will remain unchanged.
To recall a number previously stored in one of the nine addressable memory registers:
1. Press RCL.
2. Press a number key (1 through 9) to specify which of the nine registers the number is to be recalled from.
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