TUTORIAL 1: An overview of the HP48

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Hewlett Packard released their HP48 series calculators in 1991 as a successor to the well established HP41. The HP48 is perhaps the most powerful hand held calculator on the market today.

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The Display

• Status area
  • Annunciators
  • Current directory path
  • Messages
• Stack
• Command line
• Menu labels

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The Keyboard

• Primary
  The primary keyboard is represented by the labels on the face of each key.
• Left-shifted
  The left-shift keyboard is activated by pressing the purple left-shift key. The left-shifted function on the keyboard is indicated by the purple label to the top-left of the primary key.
• Right-shifted
  The right-shift keyboard is activated by pressing the turquoise right-shift key. The right-shifted function on the keyboard is indicated by the turquoise label to the top-right of the primary key.
• Alphabetical
  There are three modes of alphabetical keyboard
  • Primary alphabetical
    The alphabetical keyboard is activated by pressing the alpha key Characters are shown in white at the bottom-right of each key. Primary alpha keys are usually upper-case
  • Alphabetical left-shift
    By pressing the alpha then the left-shift key, a different character set is activated. These are generally lower-case
  • Alphabetical right-shift
    By pressing the alpha then the right-shift key, a third character set is activated. These characters are generally greek symbols.
• User
  Functions and programs can be assigned to user-specified keys.
• Menu keys
  The white keys below the menu bar activate those items in the menu. To scroll across the menu display press the NXT key
  To scroll in reverse press [L-S] [NXT] (PREV)
• Cursor keys
  
• Delete key
  This deletes the current character in edit mode, otherwise it clears the entire stack.
• Backspace key
  
• On/Cancel key
  

Terminlogy used in these tutorials

To simplify explanations, key presses are described as follows:

• Primary key     [name], ("name" is what's typed on the face of the key)
• Left-Shift         [L-S] [name] (shifted-name), (shifted-name is the left-shifted function)
• Right-Shift       [R-S] [name] (shifted-name), (shifted-name is the right-shifted function)
• Menu keys       |label|

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The HP48 stack

Last in first out (the bump up) concept
The HP48 like its predecessors uses a data stack. Numbers or other objects are entered onto the stack into level one "bumping" existing data into higher levels. The HP48's stack limit is only restricted by available memory (unlike the HP41/42 which had a stack limit of 4).

Only the first four levels of the stack are shown in the display.

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RPN operation

Reverse Polish Notation (RPN)
This is the favoured style of operation used by stack type calculators. It's named after a Pole Jan Lukasiewicz (1878-1956)

An example: add 2 & 4
    on a normal (algebraic) calculator
    2 + 4 =
    6 ( the answer )

    in RPN
    2 4 +
    6 ( the answer)

note that in RPN the = button is not used. Pressing + adds levels 1 & 2, the answer being on level one.

RPN is initially difficult for people who have used "normal" calculators all their lives, but it is a more efficient way of calculating.

Another example:

Compute (2*7)-(3*(9/11)) in RPN

    2 7 *     (the first term )
    9 11 /     (9/11)
    3 *       (the second term)
    -         the answer !

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Changing HP48 modes

It is vitally important that the settings on the HP48 are correct if programs are to work correctly.


How to set the number of decimal places displayed

• To Display all significant figures
  [L-S] [CST] (MODES) |FMT| |STD|
• To specify number of decimal places to display
  [L-S] [CST] (MODES) |FMT| n |FIX| ( n is the number of decimal places )

Angle format

• To set the calculator in DEGREES mode
  [L-S] [CST] (MODES) |ANGL| |DEG|
• To set the calculator in RADIANS mode
  [L-S] [MTH] (RADIANS)

Rectangular / Polar vector mode

• To set the calculator in Rectangular mode (x,y)
  [L-S] [CST] (MODES) |ANGL| |RECT|
• To set the calculator in Polar mode {r,theta)
  [R-S] [MTH] (POLAR)

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Last Update: 18th March 2001
Richard Stanaway