HP HP-65 - Figure 4-1. Memory, Codes, and the

mming
Thus programmed, when you pressed the [ key (in RUN mode),
the calculator searched the program memory for the correspond-
ing label ). Upon finding the label, the calculator
executed the steps following the label, one after the other in se-
quential order, until the return ([§fQ]) told the calculator to stop.
Figure 4-2 summarizes the above operations used to define
functions.
Program Memory: Program memory contains the user’s
stored program.
= Capacity: 100 locations = Top is above first location.
= Bottom is last location.
Pointer: The pointer is an internal part of the calculator.
It determines which memory location is executed or dis-
played.
Codes: In W/PRGM mode, keystrokes are stored in
memory as codes: Top of memory code is 00 00. The
codes for keys 0-9 are 00-09. For other keys, a code
denotes a row and a column. Example: Code for
(row 8, column 4) is 84.
Merged Codes: Program codes for the following are
merged with their respective prefix codes: [LsTx |,
(vorl, 7], [rv], [Re], E23, B0, B0, B4, and 1], . . .,
when prefixed by [STo or [ReL|. = Example: [&
in program mode is merged and displayed as
35 00; [STO| [5] as 33 05, etc. Note that [sTo| [9] and
[ReL! [@] are not merged.
Single Step: = In W/PRGM mode, advances the
program pointer to the next memory location, displaying
the code. Repeated use of the key enables you to re-
view a program and to position the pointer for editing.
= In RUN mode executes the program step de-
noted by the program pointer. In the case of single
stepping a call to a user defined function, (B, ..., &,
the entire function executes (as one step) before re-
turning control to the keyboard.
Figure 4-1. Memory, Codes, and the Single Step Key