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Improving Keystroke Efficiency in HP’s Recent Business Calculators

Jake Schwartz

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Some Terminology

• Keystroke Clutter is defined as the average number functions per key, or: Total number of functions Total number of keys

• Keystroke Count is defined as the average number of keystrokes per function, or:

Total number of keystrokes Total number of functions

• Keystroke Efficiency would be the reciprocal of keystroke count. – A calc with 35 primary keys would have a K.C. and a K.E. of 1.0– One with 35 keys and two shifts (with all planes full) would have

a K.C. of (33+66+66)/99 = 1.667 and a K.E. of 1/1.667 = 0.600

Primary 1st-shifted 2nd-shifted tot # fcns

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Jake’s Calculator Cardinal Rules

I. The more functions a calculator has, the better.

II. The more information which is available in the display, the better.

III. The fewer keystrokes required to execute each function, the better.

IV. Less keyboard clutter is better, but not at the expense of increased keystroke counts.

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Let’s Go Back in History…

• After all primary keys were exhausted, shifted keys were used (ex: 35 to 45)

• When shifts were full, functions were spelled out in ALPHA (Nut series)

• This evolved into menus, starting with the Clamshell series, Pioneer (and successor) two-liners and “Charlie” and “Student” machines

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Instead of These….

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What If They Had Done These?

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Initial Conclusions:

• It makes no sense to add shifted functions prior to filling up the primary keyboard, right?

• Likewise, it should not make sense to add menu functions until all the shifted positions are exhausted…..you’d think!

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So Why Did They Do These This Way?

1.431 functions per key; 1.324 functions/key,1.960 keystrokes per function 2.470 keystrokes/function

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And Why Do They Still Do It This Way?

1.324 functions per key; 1.919 functions/key,2.442 keystrokes per function 3.050 keystrokes/function

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The Burning Question• Why would they add soft-key menus prior to

filling up the shifted key positions?• Fear of intimidating the business user?

But this one (with 2 shifts) continues to sell well:

2.128 functions/key,2.796 keystrokes/function(2.044 keystrokes/function excluding the 100 “g GTO nn” program steps)

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This Current Low-Ender Also Has Two Shifts

1.975 functions/key;2.439 keystrokes/function

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Pros and Cons of Shifted Functions

• The Up Side– Functions always visible to user; no hunting– Reduced keystroke counts

• The Down Side– Increases keyboard clutter

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Minimizing Keyboard Clutter• As the number of shifted functions

increases, clutter increases

• However, function crowding may be reduced if key fronts are used as a shifted key plane– This had been abandoned with the Pioneer

and Charlie/Student calcs, but was reinstated with the 10BII, 17BII+, 35S and 20b

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The Pros and Cons of Menus

• The Up Side– Allow more functions than keyboard positions;

just about the only way to add functions when keyboard is full

– Reduces keyboard clutter

• The Down Side– Conceals functionality, sometimes requiring

“hunting” for a desired function– Increases keystroke counts, especially menus

embedded in menu “trees”

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Various Flavors of Menus

• Soft-Key Menus with bottom LCD line– 50g, 17BII+

• “Counted” Menus with numeric keys– 35S

• “Sequential” Menus with arrow keys– 20b

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Common Issues With the 17BII+ and 20b

• Need to take advantage of the unoccupied key positions on the calculator faceplate– The 17BII+ needs to have the first key plane

fully populated

• Both could improve keystroke efficiency by adding a second shift key and key plane

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Adding The Second Shift Key

HP17BII+ HP20b

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Completing the 17BII+ Original Shifted Key Plane:Exposing the Math, Printer & Modes Menu Functions

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Adding An Additional 20b Shifted Key Plane:Exposing the Math and Modes Menu Functions

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Reducing the Depth of the 17BII+ Menu Tree By

Exposing the “Main” Menu Keys On the Top Row

It would work like the HP42S: •Allow turning menu off via “EXIT” key

•When menu is off, top-row keys perform as labeled•In the 17bII++ case, these functions activate menus

•When menu is on, top-row keys act as soft keys

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Reducing the Depth of the 17BII+ Menu Tree By Exposing More Functions On Shifted Keys

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HP17BII+ Full Keyboard Upgrades: Adding Functions & Highlighting The Menu Keys

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HP20b Full Keyboard Upgrades: Adding Functions & Highlighting The Menu Keys

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Additional Improvements I:Highlighting Menu Keys a la Pioneer & HP48 Series

HP32SII

HP48SX

HP17BII++

HP20bII

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Additional Improvements II:Replacing the 17BII+ “More”/“Other” Soft Key W/ Arrow Keys

HP42S-type LCD Annunciators indicate more menu rows

Original ALPHA scheme: Revised ALPHA scheme:

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Additional Improvements II, continued:Simplifying the ALPHA-Symbols Menus

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Additional Improvements II, continued:Simplifying 17BII+ Navigation to ALPHA Symbols

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Additional Improvements III:Indicating Which 17BII+ Softkeys Are Submenus

49g+ / 50g HP17BII++

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Additional Improvements IV:Reducing the Depth of the 20b STATS Menu

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Summary of 17BII+ Improvements

1. Addition of a second shift key and shifted key plane above the physical keys2. Organizing the functions with financial/business on the upper shifted key plane and

math, modes and other items on the lower key plane3. Labelling the top row of keys with primary and shifted functions in conjunction with

allowing the soft-key menu to be optionally dismissed4. Elimination of the “MAIN” menu with its submenu functions moved to the keyboard for

direct access. Adding highlighting borders around all keyboard markings which activate menus.

5. Removal of ten soft-key menus and submenus with their functions moved out onto the keyboard. Positioning of related function keys from the same menu in proximity to each other, with keyboard markings showing their relationship.

6. Elimination of “OTHER” or “MORE” in the sixth position of multipage menus by enabling page-to-page menu navigation via the up and down arrow keys. In conjunction with this, activation of the “arrows” display annunciator whenever the currently-active menu contains multiple pages.

7. “Marking” in the LCD with a bar over top the displayed names of soft keys which point to submenus

8. Taking advantage of full six-key menus by reducing the ALPHA multipage and multi-level menu tree to fewer pages and fewer levels

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Original 17BII+ vs Proposed 17BII++

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Summary of 20b Improvements

1. Addition of a second shift key and shifted key plane above the physical keys

2. Removal of ten soft-key menus and submenus with their functions moved out onto the keyboard. Positioning of related function keys from the same menu in proximity to each other, with keyboard markings showing their relationship.

3. Adding highlighting borders around all keyboard markings which activate menus.

4. Reduction of depth of STATS menu tree via a “counted” menu (a la 35S) at the top

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Original 20b vs Proposed 20bII

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The Tallies

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Comparison of Most HP Calc Keyboards

• For exhaustive analyses of HP calculator keyboards with respect to clutter and keystroke efficiencies, consult http://www.pahhc.org/keyboards.htm on the web

• For more info on these exercises, see:– “Keyboard Clutter, Keystroke Counts & Calculator

Menus”, HPCC Datafile, V27N1P9– “Optimizing the Calculator User Interface: A Little Clutter

Can Go a Long Way”, HPCC Datafile, V27N2P7– “The HP20b Calculator: A Missed Opportunity?”, HPCC

Datafile, V27N3P17

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