Radio Shack EC-4000

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: Red  
    Display technology: Light-emitting diode 
Size: 5½"×3"×1½" Display size: 8+2 digits
Weight: 6 oz    
    Entry method: Algebraic with precedence 
Batteries: 3×"AA" NiCd Advanced functions: Trig Exp 
External power: TI AC-9132 (5.7VAC 240mA)   Memory functions: +/-/×/÷ 
    Programming model: Fully-merged keystroke entry 
Precision: 11 digits Program functions: Jump Cond Subr Lbl  
Memories: 8 numbers Program display: Keycode display  
Program memory: 50 program steps Program editing: Insert/delete capability  
Chipset: Texas Instruments   Forensic result: 9.0047463834  

ec4000.jpg (24422 bytes)Radio Shack's first programmable calculator (as far as I know) is a well-known model: none other than the venerable TI-57, Texas Instrument's first full-featured "budget" programmable machine. The only difference is the OEM labelling: otherwise, the EC-4000 is a TI-57 inside and out.

Rather than repeating my Gamma function programming example on this page, here is a simpler one: an implementation of the factorial. This program also demonstrates many of the features, including the merged programming model, if this vintage calculator.

00  86 0   LBL 0
01  32 0   STO 0
02  01     1
03  86 1   LBL 1
04  55     ×
05  33 0   RCL 0
06  56     DSZ
07  51 1   GTO 1
08  85     =
09 -61     INV SBR