PTK-1023

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: 6"×3"×1" Display size: 8+2 digits
Weight: 6 oz    
    Entry method: Reverse Polish Notation 
Batteries: 3×"AA" NiCd Advanced functions: Trig Exp 
External power:   Memory functions:  
I/O:      
    Programming model: Keystroke entry 
Precision: 8 digits Program functions:  
Memories: 1 numbers Program display:  
Program memory: 102 program steps Program editing: Step delete capability  
Chipset: National Semiconductor 4525   Forensic result:  

ptk1023.jpg (27262 bytes)A couple of years ago, I was talking to a friend of mine about my growing calculator collection, and in particular, about those OEM calculator models that were produced in Hungary around the time when we were in high school. He surprised me greatly when he mentioned a model I never heard of before; a PTK calculator that was, according to his recollection, an OEM version of a National Semiconductor (Novus) programmable.

Eventually, I was able to get more information about this mysterious machine and now, I finally have one in my possession. And a Novus machine it is: none other but the Scientist PR, one of the early Novus programmables. It is in reasonably good shape, too, working fine; sadly, most of the instruction panel on the black is no longer legible, as the printing wore off over the years.

One mystery remains. The model numbers of other PTK calculators are derived from the number of program steps stored by the calculator. The PTK-1050 has 50, the PTK-1072 has 72, and the PTK-1096 has 960 program steps. But it's hard to see how the model number of the PTK-1023 relates to its 102 step program capacity.

Like other early Novus programmables, the PTK-1023 offers no conditional or jump instructions, nor is there any way to review or correct a program. Nevertheless, a generous 100 program steps combined with the RPN programming model make this a capable calculator. Its main shortcoming is the great inaccuracy of the built-in scientific functions, especially its trigonometric functions.

The programming model is well demonstrated by the following implementation of the Gamma function, which remains my preferred programming example. Using barely more than half the program capacity of the calculator, this program computes the logarithm of the Gamma function for any argument greater than 2 to the maximum accuracy possible on this machine.

MS
EN
ln
×
MR
-
2
π 
×
MR
÷
√ 
ln
+
MR
MR
×
1/x
9
9
÷
1
4
0
1/x
-
MR
÷
MR
÷
1
0
5
1/x
+
MR
÷
MR
÷
3
0
1/x
-
MR
÷
MR
÷
1
+
1
2
÷
MR
÷
+