Hewlett-Packard HP-200LX

Datasheet legend
Ab/c: Fractions calculation
AC: Alternating current
BaseN: Number base calculations
Card: Magnetic card storage
Cmem: Continuous memory
Cond: Conditional execution
Const: Scientific constants
Cplx: Complex number arithmetic
DC: Direct current
Eqlib: Equation library
Exp: Exponential/logarithmic functions
Fin: Financial functions
Grph: Graphing capability
Hyp: Hyperbolic functions
Ind: Indirect addressing
Intg: Numerical integration
Jump: Unconditional jump (GOTO)
Lbl: Program labels
LCD: Liquid Crystal Display
LED: Light-Emitting Diode
Li-ion: Lithium-ion rechargeable battery
Lreg: Linear regression (2-variable statistics)
mA: Milliamperes of current
Mtrx: Matrix support
NiCd: Nickel-Cadmium rechargeable battery
NiMH: Nickel-metal-hydrite rechargeable battery
Prnt: Printer
RTC: Real-time clock
Sdev: Standard deviation (1-variable statistics)
Solv: Equation solver
Subr: Subroutine call capability
Symb: Symbolic computing
Tape: Magnetic tape storage
Trig: Trigonometric functions
Units: Unit conversions
VAC: Volts AC
VDC: Volts DC
Years of production: 1990-? Display type: Graphical display  
New price:   Display color: Black  
    Display technology: Liquid crystal display 
Size: 6"×6"×1" Display size: 640×200 pixels
Weight: 12 oz    
    Entry method: Spreadsheet calculation 
Batteries: 2×"AA" alkaline + 1×"CR-2032" Lithium Advanced functions: Trig Exp Lreg Grph Solv Fin Cmem RTC Snd Mtrx BaseN 
External power: HP adapter   Memory functions: +/-/×/÷ 
I/O: Serial port, IR port, PCMCIA     
    Programming model: Spreadsheet data 
Precision: 16 digits Program functions: Jump Cond Subr Lbl Ind  
Memories: 1(0) megabytes Program display: Formula display  
Program memory: 1 megabytes Program editing: Formula entry  
Chipset: Intel 80x86   Forensic result:  

*Also available with 2 and 4 MB or memory.

hp200lx.jpg (52917 bytes)The HP-200LX was Hewlett-Packard's last non-Windows handheld computer. An advanced pocket computer that is eminently practical even today, the HP-200LX was equipped with MS-DOS 5.0, Lotus 1-2-3, and a suite of other applications loaded in ROM. But the main reason why it found itself in a collection dedicated to programmable calculators is that it was also the last HP pocket computer prominently featuring a powerful calculator applet... later, Windows CE models came with that dinky little Windows calculator, that's all.

As a formula programmable calculator, the calculator "applet" in the HP leaves very little to be desired. It can operate as an algebraic or RPN calculator; it can store, evaluate, and solve formulae of practically arbitrary length and complexity; and it is even integrated with the built-in Lotus 1-2-3 spreadsheet. It is also a graphic calculator; the graphical image to the right was produced using a Gamma function formula similar to the following:

Gamma=(-1)^SIGMA(i,X,0,1,1)/EXP(SIGMA(
i,X,15,1,LN(ABS(i))))*L(q,SIGMA(i,X,15
,1,1)+X)^q/EXP(q)*SQRT(2*PI/q)*EXP((((
(1/1188/SQ(q)-1/1680)/SQ(q)+1/1260)/SQ
(q)-1/360)/SQ(q)+1/12)/q)

Curiously, the HP-200LX also has a second calculator applet "hidden" in one of its system directories. It is a programmers' calculator that can do integer math in the binary, octal, decimal and hexadecimal number basis.

But most importantly, the HP-200LX is a good quality MS-DOS computer. Unlike its smaller cousin, the HP-95LX, the HP-200LX has a full-sized (640x240 pixel) screen, which makes this machine compatible with any application that can use a CGA resolution display. I've used diverse applications, including the EDIT.COM editor from Windows NT, or the classic INFOCOM game Beyond Zork on this machine.

The one thing that this machine lacks is a built-in development system for creating "native" applications, i.e., MS-DOS executables. Oh, it does have a copy of the MS-DOS debugger DEBUG.COM, but it's of very little use, unless you can routinely write programs using a line assembler.  It was this lack of a native development system that inspired me to invent, and implement, a programming language that makes it possible to write simple MS-DOS programs on the HP-95LX or the HP-200LX. Of course, I should hasten to add, that as the HP-200LX is a machine with good MS-DOS compatibility, many older (16-bit) development tools can be used on it, including some Borland tools that are now available from the Borland Web site as a free download.