HP 35s Programming

Programs can be used for repetitive calculations - calculations that may involve more input or output control and intricate logic. You can use the hp 35s to enter a program which will allow the repetition of operations and calculations in a precise manner desired.

To enter a program into hp35s memory

Press {LeftShift}, then {PRGM} to activate Program-entry mode.

Press {LeftShift}, then {GTO}, {.}, then {.} to display PRGM TOP. This sets the program pointer to a known spot, before any other programs. As the program lines are entered, they are inserted before all other program lines. If other programs that might be needed in memory are not needed, clear program memory by pressing {LeftShift}, {CLEAR}, then {PGM}. To confirm that all programs are deleted, press Y after the message "CL PGMS? Y N".

Give the program a label--a single letter, A through Z. Press {LeftShift}, then LBL, then letter. Choose a letter that will indicate the nature of the program, such as ’A" for "area". If the message "DUPLICAT.LBL" is displayed, use a different letter. The existing program can be cleared instead--press {LeftShift}, MEM, then PGM, use {LeftShift}, then cursor-up or {LeftShift}, then cursor-down to find the label, and press {LeftShift}, then {CLEAR}, and {C}.

To record calculator operations as program instructions, use the same keys that would be pressed to perform operations manually. Remember that many functions do not appear on the keyboard, but must be accessed using menus. To enter an equation in a program line, see the instructions below.

End the program with a return instruction, which sets the program pointer back to PRGM TOP after the program runs. Press {RS}, then {RTN}.

Press C (or {LeftShift}, then {PRGM}) to cancel program entry.
Numbers in program lines are stored precisely as entered, and they are displayed using ALL or SCI format. (If a long number is shortened in the display, press {RS}, then SHOW to view all digits.)

To enter an equation in a hp35s program line

Press {RS}, then {EQN} to activate Equation-entry mode. The EQN annunciator turns on.

Enter the equation similar to entering an equation in the equation list. Use {LeftShift}, then {CLEAR} to correct errors while typing.
Press ENTER to terminate the equation and display its left end. (The equation does not become part of the equation list.)

After the equation has been entered, press RS, then SHOW to see its checksum and length. Hold the SHOW key to keep values in the display.
Use SUM+ and SQx to scroll the display. Press RS, then SCRL to turn off scroll and use the top-row keys to enter program instructions.

Keys that clear hp35s program entry

Note these special conditions during program entry:

{C} always cancels program entry. It never clears a number to zero.
If the program line does not contain an equation, {LeftShift}, then CLEAR deletes the current program line. It backspaces if a digit is being entered ("_" cursor present).

If the program line contains an equation, {LeftShift}, then CLEAR begins editing the equation. It deletes the rightmost function or variable if an equation is being entered. {LeftShift}, CLEAR, then EQN deletes a program line if it does not contain an equation.

To program a function to clear the X-register, use {LeftShift}, {CLEAR}, then select X.

Function names in programs

The name of a function that is used in a program line is not necessarily the same as the function’s name on the key, in its menu, or in the equation. The name that is used in a program is usually a fuller abbreviation than that which can fit on a key or in a menu. This fuller name appears briefly in the display whenever a function is executed - as long as the key is held down, the name is displayed.

Example of entering and running a simple program

To find the area of a circle with the radius of 5, use the formula A = pi r2m and press {5}, {LeftShift}, {x2} , {RS}, {pi}, then {x} to get the result for this circle: 78.5398.

To find the areas of many different circles, it is not necessary to repeat the given keystrokes each time (vary only the "5" for the different radii). The repeatable keystrokes can be put into a program:

001 x2
002 pi
003 x

This very simple program assumes that the value for the radius is in the X-register (the display when the program starts to run. It computes the area and leaves it in the X-register. To enter this program into the program memory, do the following:

  • Press {LeftShift}, {CLEAR}, {ALL}, then select Y to clear the HP35S memory.
  • Press {LeftShift}, then {PRGM}, this will activates HP35S Program-entry mode (PRGM annunciator on).
  • Press {LeftShift}, {GTO}, {.}, then {.} It will display [ PRGM TOP ], this resets HP35S program pointer to PRGM TOP.
  • Press {LeftShift}, then {x2} Display [ 001 x2 ] equals to (Radius) 2
  • Press {RS}, then {pi} Display [ 002 pi ]
  • Press {x} Display [ 003 x ], which is Area = pi x2
  • Press {LeftShift}, then {PRGM}, This will exit HP35S Program-entry mode.

Try running this program to find the area of a circle with a radius of 5:

  • Press {5}, {LeftShift}, {GTO}, {.}, then {.} Display [ 5.0000 ] sets the program to its beginning
  • Press {R/S} Display [ 78.5398 ] this is the answer.

The above procedures are applicable for HP33s.

Tagged By: HP 33s, HP 33s, HP 33s, HP 33s, HP 33s.


  1. On 09-Apr-2014, Anonymous wrote: 
    [N,E] means vectors. The square brackets are only used for vectors which are sets of 2 or 3 numbers, separated by commas. So it sounds like (if right-shift is BLUE and left-shift is YELLOW): first of all hit EQN, then BLUE [] RCL N YELLOW , RCL E > That should work! The square-brackets is the same button as the round brackets () and the letter P, 5th row from the bottom. The comma is on the same key as the 0, on the bottom row. The > means one of the arrow-keys at the top.

    In Equation mode (EQN), you can spell words, so you hit the EQN button and then hit the RCL button before each letter, so RCL K RCL O RCL B RCL O RCL L RCL D will spell "KOBOLD". You can even get spaces with (BLUE) SPACE, the 0 key in the bottom row, and for dashes use the minus (-) sign.
    Your reply to Anonymous

  2. On 06-Nov-2013, Me wrote: 
    I am trying to type in a program step and having trouble. The book says the display should look like this. [N,E] I cant figure out how to get the brackets on the coma to come up. The book list the step like this, EQN press RCL before each character. Im not having any problems with the letters. Its just the symbols that are giving me a fit. Thanks for any help you can give.
    Your reply to Me
    • On 09-Apr-2014, Pierre Savoie replied: 
      [N,E] means vectors. The square brackets are only used for vectors which are sets of 2 or 3 numbers, separated by commas. So it sounds like (if right-shift is BLUE and left-shift is YELLOW): first of all hit EQN, then BLUE [] RCL N YELLOW , RCL E > That works! The square-brackets is the same button as the round brackets () and the letter P, 5th row from the bottom. The comma is on the same key as the 0, on the bottom row. The > means one of the arrow-keys at the top.
      Your reply to Pierre Savoie

  3. On 08-Feb-2013, Yunga Baru wrote: 
    i need calculator hp35s program calculator, Pls email me you programe. i need it for surveying work
    Your reply to Yunga Baru
    • On 09-Apr-2014, Pierre Savoie replied: 
      You should do a search on the Web using the words HP35 programs programming. When you do so, there is one page with a lot of programs for surveyors and engineers that is just what you are looking for: www.wollindina.com/HP-35S/


      There is an entire booklet for you if you cut and paste this in your browser:

      www.quickclose.com.au/hp35surveyprogsEvaluation.pdf
      Your reply to Pierre Savoie

  4. On 22-Sep-2012, Alex wrote: 
    How could I possibly type " EQN KOBOLD " in my hp 35s calculator.
    PS: It’s for a game written by Paul Dale on hpmuseum.org
    Thanx
    Your reply to Alex
    • On 22-Sep-2012, Peter Tong replied: 
      You are right, it is a pretty long list to enter....
      http://www.hpmuseum.org/cgi-sys/cgiwrap/hpmuseum/articles.cgi?read=1035
      Your reply to Peter Tong
    • On 09-Apr-2014, Pierre Savoie replied: 
      In Equation mode (EQN), you can spell words, so you hit the EQN button and then hit the RCL button before each letter, so RCL K RCL O RCL B RCL O RCL L RCL D will spell "KOBOLD". To choose your letters look only at the pinkish letters on the bottom right side of each key. You can even get spaces with (BLUE) SPACE (the left-shift key and then the 0 key in the bottom row), and for dashes use the minus (-) sign.
      Your reply to Pierre Savoie

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