HP HP-15C - Memory Requirements for the Advanced Functions

218 Appendix C: Memory Allocation
Your very first program instruction will commit R
65
(all seven bytes) from
an uncommitted register to a program register. Your eighth program
instruction commits R
64
, and so on, until the boundary of the common pool
is encountered. Registers from the data storage pool (at power-up, this is R
19
and below) are not available for program memory without reallocating
registers using m %.
Two-Byte Program Instructions
The following instructions are the only ones which require two bytes of
calculator memory. (All others require only one byte.)
´ b . label
´ > {0 to 9}
t . label
´ X {2 to 9, .0 to .9}
| " (n or V)
´ e {2 to 9, .0 to .9}
|F (n or V)
´ I {2 to 9, .0 to .9}
| ? (n or V)
O {+, -, *, ÷}
´ • (n or V)
l {+, -, *, ÷}
´ i (n or V)
O > {A to E}
´ ^ (n or V)
O {A to E, %} in User
mode
´ _
l {A to E, %} in User
mode
´ f
O | %
l | %
Memory Requirements for the Advanced Functions
The four advanced functions require temporary register space from the
common register pool.
Function
Registers Needed
_
f
5
23
23 if executed
together
Complex Stack
5
Matrices
1 per matrix element