HP HP-67 - Storage Register Arithmetic

Storing and Recalling Numbers 81
Storage Register Arithmetic
You can, of course, perform arithmetic (or any other function) in the
normal manner by recalling and using the contents of any storage
register just as if it were a number you keyed in. The HP-67 also
permits you to perform storage register arithmetic in storage registers;
that is, arithmetic upon the contents of the selected register.
Storage register arithmetic can be performed directly upon the contents
of primary registers R, through Ry only; it cannot be performed
directly upon any other storage register. (However, storage register
arithmetic can be performed indirectly upon the contents of any
storage register, as you will see in section 12, Using the
I-Register for Indirect Control.)
To perform storage register arithmetic directly, press Eifel followed
by the arithmetic function key followed in turn by the number key
((9) through (9)) of the primary register address. For example:
Press Result
1 Number in displayed X-register added to contents of
primary storage register R;, and sum placed into Ry;
(r;y + x =>Ry).
B 2 Number in displayed X-register subtracted from
contents of primary storage register R,, and difference
placed into Ry; (1, — x = Ry).
3 Number in displayed X-register multiplied by contents
of primary storage register R, and the product placed
into Rg; |(r5) x = Ry |.
B 4 Contents of storage register R, divided by number in
displayed X-register, and quotient placed into register
Ry (ry + x = RY).
When
storage
register
arithmetic
operations
are
performed,
the
answer
is
written
into
the
selected
storage
register,
while
the
contents
of
the
other
storage
registers
and
the
displayed
X-register
and
the
rest
of
the
stack
remain
unchanged.