HP 15c Scientific m%, bytes, where:, dduu pp-b, The m%Function, = the number of, Memory Status (W), Appendix C: Memory Allocation

Appendix C: Memory Allocation 215

Memory Status (W)To view the current memory configuration of the calculator, press W(memory), holding W to retain the display.* The display will be four numbers,dduu pp-b

where:

dd= the number of the highest-numberedregister in the data storagepool (making the total number of data registers dd + 2 because of R0 and RI);uu= the number of uncommitted registers in the common pool;pp= the number of registers containing program instructions; and

b= the number of bytes left before uu is decremented (to supply seven more bytes of program memory) and pp is incremented.

The initial status of the HP-15C at power-up is:

19 46 0-0

The movable boundary between the data storage and common pools is always between Rdd and Rdd + 1.

Memory Reallocation

There are 67 registers in memory, worth seven bytes each. Sixty-four of these registers (R2 to R65) are interconvertible between the data storage and common pools.

The m%Function

If you should require more common space (as for programming) or more data storage space (but not both simultaneously!), you can make the necessary register reallocation using m%.† The procedure is:

*MEM is nonprogrammable.

†m (dimension) is so called because it is also used (with A through E or V) to dimension matrices. Above, however, it is used (with %) to ―dimension‖ the size of the data storage pool.