HP 9100B Operating & Programming Manual page 87

PROGRAMMING THE 91008
PROGRAM OPERATION
Each time the STEP PRGM is pressed the program counter
is incremented by one count. The X regtster wtll display
the last program step address and the octal code for the
program step at that address. The Z register will display
the next program address and the instruct1on in that ad -
dress.
NOTE
When in the PROGRAM mode pressing any key, other
than STEP PRGM , will cause that instructton to be
entered as a program step.
As an example, step through the program previously used
(Page 66) and observe that the correct address and
(octal) key codes are displayed in the X register. Switch
back to RUN mode any time the program counter is to be
re-add ressed.
2. RUN MODE: used to verify that the program will operate
as written.
SWITCH: RUN
PRESS:
~~~T~
(
+
or - )
Starting
Address
Press the STEP PRGM key at each step; data must be en -
tered at the correct program steps to check operation and
solution of the program . At each step the X, Y and Z regi s-
terswill display the results of the operatton .
ln the RUN mode (only), these instructions will not act as
expected when the STEP PRGM key is being used:
CONT
FMT
tF tF
X<Y
x:y
IF
x>y
IF
FLAG
lf CONTinue is included in the program , thi s step must be
replaced by a STOP or PAUSE instruction (see CORRECT-
ING A PROGRAM, for this procedure) before the program
can be edited in the RUN mode. The calculator will auto-
matically continue execution of the program any time a
CONT instruction is encountered .
When STEP PRGM is pressed at a FMT instruction both
the FMT and the next instruction are read ; the next time
STEP PRGM is. pressed the secend in struction after the
FMT will be executed.
The 'conditional' branch instruction s (IF FLAG, IF x
< Y,
JF x
=
y, IF x ,; y) cause the program counter to branch
77