HP HP-67 - Page 190

186 Branching
The conditional operations on your HP-67 keyboard are useful as
program instructions to allow your calculator to make decisions like
the one shown above. The eight conditionals that are available on your
HP-67 are:
a8 tests to see if the value in the X-register is equal to the value
in the Y-register.
a tests to see if the value in the X-register is unequal to the
value in the Y-register.
a8 tests to see if the value in the X-register is less than or equal
to the value in the Y-register.
a tests to see if the value in the X-register is greater than the
value in the Y-register.
tests to see if the value in the X-register is equal to zero.
tests to see if the value in the X-register is unequal to zero.
a tests to see if the value in the X-register is less than zero.
D tests to see if the value in the X-register is greater than zero.
Each conditional essentially asks a question when it is encountered as
an instruction in a program. If the answer is YES, program execution
continues sequentially downward with the next instruction in program
memory. If the answer is NO, the calculator branches around the
next instruction. For example:
Conditional Test ——
Yes |
‘ No
4——!