Sunday, October 22, 2017

Retro Review: HP 95LX

Retro Review:  HP 95LX


Company:  Hewlett Packard
Years:  1991 - 2003
Type:  Palmtop PC (a very early version of the laptop)
Applications:  HP Calc, Lotus 1-2-3, Memo, Phone, DOS Prompt
Memory:  512,000 byte ROM, 1 MB RAM
Operating System: Microsoft MS-DOS 3.22
Original Price:  around $550 to $699
Today’s Price: can be very reasonable, anywhere from $40 to upwards of $200

Batteries:  2 AA batteries to run it, 1 CR2032 backup battery, can be powered by AC connector

This review will mainly focus on the HP Solve and Lotus 1-2-3 apps, as if I had not have the chance to try other apps at the time of this review.

Special Thanks

Thank you to Dave Bitten for this wonderful computer! This is the first portable computer of the 1990s HP series that I have.  I traded my Casio fx-Algebra 2.0.


The HP 95LX has a rich variety of applications, including:

*  Appointment Book
*  Phone Book
*  Memo
*  Lotus 1-2-3
*  HP Calc (what the HP 19C would look like if it became a graphing calculator)

The HP 95LX can also hold a RAM disk, for permanent storage. 

HP Calc

The HP Calc is based off the HP 19B calculator, but adds a graphing calculator component.  The HP Calc can be operated for in either Algebraic or RPN (reverse polish notation).  HP Calc had financial solvers (time value of money, interest conversion, cost/sell/margin/markup), conversions (currency, length, area, volume, mass), and scientific functions (random numbers, logarithms, exponentials, trigonometry), and list editor.   

The solver is also based off the HP 19B, and also includes all the advanced features of the type of solver that was present on the HP 17BII+, HP 17B, and HP 27S.

* IF:  If statement with one command then and else command.  If statements can be nested.
* SIGMA:  The sum of a sequence.  The increment is specified.  Similar to Σ(f(x), x=a, b).
* S:  Solve:  Used in an IF statement, dictates which calculations to make depending of which variable is solved.
*  L:  Let: stores a value in a variable during a formula.
* G:  Get: recalls a variable during a formula

Example:  0*L(var:f(var)) + h(G(var) and other constants)

Lotus 1-2-3

Before Microsoft Excel, Lotus 1-2-3 was the favorite of spreadsheet applications.  Lotus 1-2-3 is easy to use with a good resource, like the awesome HP 95LX manual, download here:

What is really nice about the Lotus 1-2-3 is the ease of creating macros.  The only caveat is the macro is typed in code (depending on key stroke, such as \ for Menu, the first letter to choose commands, a tilde (~) for an enter, and other commands to move the cursor or ask for input).  Macros are assigned to the keyboard (called by Alt + letter). 

On Lotus 1-2-3, date functions handle years between 1900 and 2099.


The ON key toggles the HP 95LX on and off.  No waiting for the computer to start up, which is nice.  The keyboard is a QWERT keyboard.  Even though the keys are little small, they are pleasure to press and keys are responsive. 


I am also impressed with HP 95LX’s sharp display.  The text on screen is very readable. The screen is not backlit, understandable for the technology of the early 1990s, which backlighting would put a high demand on its battery. 

Verdict… so far

I am very happy to have an HP 95LX.  If (really when) I get a chance, I want to take a look at DOS programming, playing around and expanding the limits of both HP Calc’s solver and Lotus 1-2-3.  So far, so good. 


Hewlett Packard.  “History of the HP 95LX computer”  Retrieved October 17, 2017. 


This blog is property of Edward Shore, 2017

Texas Instruments: TI-36X Pro and TI-30X Pro Mathprint

 Essentially, the Texas Instruments TI-36X Pro and the TI-30X MathPrint are functionally equivalent.  What makes the two calculators differe...