Truly SC111

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: 5"×3"×½" Display size: 10+2 digits
Weight: 3 oz    
    Entry method: Algebraic with precedence 
Batteries: 2×"G-10" Silver-Oxide Advanced functions: Trig Exp Hyp Lreg Intg Ab/c Cplx Cmem BaseN Const Eqlib 
External power:   Memory functions: +/-/×/÷ 
    Programming model: Fully-merged keystroke entry 
Precision: 12 digits Program functions: Jump Cond  
Memories: 7 numbers Program display:  
Program memory: 29 program steps Program editing:  
Chipset:   Forensic result:  

sc111.jpg (30643 bytes)This curious little calculator is an enigmatic machine. Its features, keyboard layout, programming model, and many of its idiosyncrasies suggest that this is just a Casio calculator in OEM disguise. But I am not aware of any Casio machine with exactly the same set of features (although the fx-50F comes pretty darn close.) Moreover, there are some intriguing differences; most notably, Mike Sebastian's forensics test produces a previously unknown result. So the question remains open: is this really a Casio, or is it a copycat model?

The SC111 is a surprisingly pleasant and capable calculator. Inside the small, but relatively sturdy package is a machine with a comprehensive set of scientific, statistical, and binary arithmetic functions, a built-in formula library with 39 preprogrammed formulae, and even 9 physical constants, made particularly useful by keyboard labeling that indicates, in addition to the constant's name, the unit of dimensions in which the constant is represented.

Alas, the SC111 has the same amount of program memory as the most limited programmable Casio machines: a mere 29 program steps. A fully merged programming model helps, but even so, a machine this capable should have been equipped with a more generous amount of programming space.

Yet it is actually possible to write useful non-trivial programs in 29 steps. This is demonstrated by an implementation of the incomplete Gamma function shown for the Radio Shack EC-4024 (an OEM version of the Casio fx-50F). Here is another program, one which supplements Stirling's formula with a simple iteration to compute the logarithm of the Gamma function to 6-digit accuracy. Prior to using this program, you must store the value 2π in the calculator's independent memory:

01	+
02	ln
03	Kin+ 1
04	1
05	=
06	x<=M
07	+
08	x-K 1
09	-
10	Kout 1
11	×
12	ln
13	-
14	(
15	MR
16	÷
17	Kout 1
18	)
19	√ 
20	ln
21	x-y
22	+
23	1
24	2
25	1/x
26	÷
27	0
28	x-K 1
29	=