Hewlett-Packard HP-71B

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: 1984-1989 Display type: Alphanumeric display  
New price: USD 525.00   Display color: Black  
    Display technology: Liquid crystal display 
Size: 4"×8"×1" Display size: 22 characters
Weight: 12 oz    
    Entry method: Formula entry 
Batteries: 4×"AAA" alkaline Advanced functions: Trig Exp Cmem RTC Snd Card 
External power: HP-82059 adapter (8VAC 3W)   Memory functions:  
I/O: HP-IL, expansion ports     
    Programming model: BASIC 
Precision: 13 digits Program functions: Jump Cond Subr Lbl Ind  
Memories: 16(0) kilobytes Program display: Text display  
Program memory: 16 kilobytes Program editing: Text editor  
Chipset: Saturn   Forensic result: 8.99999864267  

hp71b.jpg (33112 bytes)Having expressed my dislike for another Hewlett-Packard BASIC-programmable handheld calculator, the HP-75C earlier, I was surprised to find that the HP-71B is a much more likeable machine. Is it the separate numeric keypad and the calculator mode? Is it the smaller size? I don't know what the cause, but I consider the HP-71B a much friendlier beast.

Yes, this is a BASIC-programmable handheld computer, and I guess that even at the time of its introduction, it had a hard time to compete with much cheaper models from Casio and others. One thing going for it is quality; the HP-71B has that solid HP "feel", a high-quality keyboard, optional HP-IL connectivity, and a wealth of accessories including an optional magnetic card reader.

Another claim of fame: the HP-71B was the first Hewlett-Packard calculator/computer to use the then new Saturn CPU architecture. This microprocessor has since been used in all high-end HP calculators, including the HP-28 and HP-48 series, and the new HP-49G.

The BASIC programming model of the HP-71B is practically identical to that of the HP-75. Unlike many other handhelds BASIC machines, the HP-71B lets you organize your programs in main memory into named files; these files can then be managed, or copied to or from peripherals. (To save the current file to a card, you'd type COPY TO CARD; to load it later, use COPY CARD.)

A good CPU means fast execution; this lets me present another variation on my favorite theme, the Gamma function. Calculating the incomplete Gamma function takes only a few tens of seconds for most reasonable pairs of values using the program below. It actually implements the incomplete Gamma function as a user-defined function; for instance, to calculate the incomplete Gamma function for the argument 5, with an integration limit of 45, you'd type FNG(5,45). Needless to say, the machine must not be in calculator mode when you enter or run this program.

20 G=X^A/EXP(X)/A
30 T=G
40 A=A+1
50 T=T*X/A
70 G=G+T
80 GOTO 40
90 FNG=G