Panasonic JE-554U

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:   Display type: Numeric display  
New price:   Display color: Black  
    Display technology: Liquid crystal display 
Size: 6½"×3½"×½" Display size: 10+2 digits
Weight: 4 oz    
    Entry method: Algebraic with precedence 
Batteries: 2×"V389" button cell Advanced functions: Trig Exp Hyp Lreg Ab/c Cplx Cmem BaseN Units Const 
External power:   Memory functions: +/-/×/÷/^ 
I/O:      
    Programming model: Partially merged keystroke 
Precision: 12 digits Program functions: Jump Cond  
Memories: 10 numbers Program display:  
Program memory: 128 program steps Program editing:  
Chipset: Toshiba T7942S   Forensic result: 8.99999863704  

je554u.jpg (35826 bytes)This Panasonic calculator has a different keyboard layout, but it is functionally identical to the Canon F-802P. Both calculators, and several other functionally identical models from various manufacturers appear to be based on the same Toshiba programmable calculator integrated circuit.

This is a fairly no-compromise machine with a comprehensive set of scientific and statistical functions, and even a built in constants library and unit conversions. My biggest gripe is that it provides no mechanism for reviewing or editing programs: program code is entered blindly. This makes its otherwise powerful programming model (128 partially merged steps, conditional jump capability) unnecessarily difficult to utilize fully.

Not uncommon among "programming in the blind" models, this machine even has that atrocious "feature" that the display register is cleared whenever you switch to program entry mode. If you are trying to enter an algorithm that yields an error for a null argument, well... good luck! (Fortunately, on the JE-554U it is possible to hit the CE/C key, which will not register as a program step, but clears the error condition and lets you continue program entry.)

My other gripe? Well... this Panasonic machine just feels wrong in one's hands. It's needlessly large: it's also very thing, giving an impression of fragility.

The following programming example demonstrates the programming model of the JE-554E through an implementation of the logarithm of the Gamma function based on Stirling's formula:

STO
0
1
STO
1
5
x<=M 8
RCL
0
STO
×
1
1
M+
GOTO -9
1
1
8
8
1/x
÷
RCL
0
x2
-
1
6
8
0
1/x
=
÷
RCL
0
x2
+
1
2
6
0
1/x
=
÷
RCL
0
x2
-
3
6
0
1/x
=
÷
RCL
0
x2
+
1
2
1/x
=
÷
RCL
0
+
RCL
0
*
RCL
0
ln
-
RCL
0
+
(
2
×
π 
÷
RCL
0
)
ln
÷
2
-
RCL
1
ln
=