Section 5
Storing and Recalling Numbers and ALPHA Strings
Your HP-41C comes standard with 63 storage registers. You can add memory modules to increase the number of registers to a total of 319.
In the HP-41C, program memory also uses storage registers for the storage of program instructions. In fact, you can control the amount of memory space that is allocated to both data storage registers and program memory. You will learn how to control these allocatios later in this section. When you first turn the HP-41-C on, it has 17 primary storage registers and 46 registers of program memory.
The HP-41C data storage registers allow you to manually store and recall numbers and ALPHA strings for use in later calculations or in programs. These registers are independent of the automatic memory stack and LAST X registers. Like most functions, you can use these storage registers either from the keyboard or as part of a program. All information in the storage registers is preserved by the Continuous Memory of the calculator.
The diagram below shows all potential data storage registers. This diagram shows data storage registers in their maximum memory allocation. Remember, unless you have added additional memory modules, your HP-41C has up to 63 primary storage registers. The addresses of the extended storage registers are indicated by the numbers (100) through (318).
Automatic  
Memory  
Stack  
T  
Z ALPHA
Y  
X LAST X
If all memory modules where allocated to storage registers, each additional module would account for the following register addresses:
Primary
Data Storage
Registers
R00
R01
R02
·   
·   
R62
R63  
R64  
·     
·     
R99  
 
 
 
 
The standard
HP-41C has
63 (R00-R62)
primary storage
registers.
Extended
Data Storage
Registers
R(100)
R(101)
R(102)
·
·
R1 · R1
R1 · R1
R1 · R1
·
·
R(318)
 
 
 
 
 
You can add up to four memory modules, bringing the total to 100 primary and 219 extended storage registers.
Standard: R00-R62
Module 1: R63-R99, R(100)-R(126)
 
Module 2: R(127)-R(190)
Module 3: R(191)-R(254)
 
Module 4: R(255)-R(318)
 
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