HP 15c Manual

 Section 5: The Display and Continuous Memory 61 
 
 
Digit Separators 
The  HP-15C is set  at  power-up  so  that  it  separates  integral  and  fractional 
portions  of  a  number  with  a  period  (a  decimal  point),  and  separates  groups 
of  three  digits  in  the  integer  portion  with  a  comma.  You  can  reverse  this 
setting  to  conform  to  the  numerical  convention  used  in  many  countries.  To 
do  so,  turn  off  the  calculator.  Press  and  hold =,  press  and  hold ., 
release...

62 Section 5: The Display and Continuous Memory 
 
Low-Power Indication 
When  a  flashing  asterisk,  which  indicates 
low  battery  power,  appears  in  the  lower 
left-hand  side  of  the  display,  there  is  no 
reason  to  panic.  You  still  have  plenty  of 
calculator  time  remaining:  at  least  10 
minutes  if  you  continuously  run  programs, 
and  at  least  an  hour  if  you  do calculations 
manually.  Refer  to  appendix  F  (page  259) 
for information on replacing the batteries....

 Section 5: The Display and Continuous Memory 63 
 
 
Resetting Continuous Memory 
If  at  any  time  you  want  to  reset  (entirely  clear)  the  HP-15C Continuous 
Memory: 
1. Turn the calculator off. 
2. Press and hold the = key, then press and hold the - 
key. 
3. Release the = key, then the - key. (This convention 
is represented as = / -.) 
When  Continuous  Memory  is  reset, Pr  Error (power  error) will  be 
displayed. Press any key to clear the display. 
Note: Continuous  Memory  can...

 
 
 
 
 
Part ll 
HP-15C 
Programming  

 
66 
Section 6 
Programming Basics 
The  next  five  sections  are  dedicated  to  explaining  aspects  of  programming 
the  HP-15C.  Each  of  these  programming  sections  will  first  discuss  basic 
techniques  (The  Mechanics),  then  give  examples  for  the  implementation  of 
these  techniques  (Examples),  and  lastly  discuss  finer  points  of  operation  in 
greater detail (Further Information). Read only as far as you need to support 
your use of the HP-15C. 
The Mechanics 
Creating a...

 Section 6: Programming Basics 67 
 
Location  in  Program  Memory.  Program  memory – and  therefore  the 
calculators  position  in  program  memory – is  demarcated  by  line  numbers. 
Line  000  marks  the  beginning  of  program  memory  and  cannot  be  used  to 
store  an  instruction.  The  first  line  that  contains  an  instruction  is  line  001. 
Program  lines  other  than  000  do  not  exist  until  instructions  are  written  for 
them. 
You can start  a  program  at  any  existent...

68 Section 6: Programming Basics 
 
 
Keystrokes Display  
2 002-         2   
* 003-        20  
9 004-         9 Given h in the X-register, 
lines 002 to 008 calculate . 005-        48 
8 006-         8 
. ÷ 007-        10 
¤ 008-        11 
Program End. There are three possible endings for a program: 
 | n (return) will end a program, return to line 000, and halt. 
 ¦ will stop a program without moving to line 000. 
 The end of program memory contains an automatic n. 
Keystrokes Display  
|n 009-...

 Section 6: Programming Basics 69 
 
 
Keystrokes Display  
|¥  Run mode; no PRGM annunciator 
displayed. (The display will depend 
on any previous result.) 
The  position  in  program  memory  does  not  change  when  modes  are 
switched.  Should  the  calculator  be  shut  off,  it  always  ―wakes  up‖  in 
Run mode. 
Executing  a  Program. In Run  mode, press ´ letter  label or G digit 
(or  letter) label.  This  addresses  a  program  and  starts  its  execution.  The 
display will flash running....

70 Section 6: Programming Basics 
 
This is the  method used above, where h was placed in the X-register 
before  running  the  program.  No v instruction  is  necessary 
because  program  execution  (here: ´A) both  terminates  digit 
entry  and  enables  the  stack  lift.  The  above  program  then  multiplied 
the contents of the X-register (h) by 2. 
The  presence  of  the  stack  even  makes  it  possible  to  load  more  than 
one  variable  prior  to  running  a  program.  Keeping  in  mind  how...