Technico PSR-98
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 |
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Technico PSR-98
This Taiwanese programmable calculator (remember when so many electronic gizmos used to be made in Taiwan? Not anymore; most are made in China nowadays) is yet another OEM machine containing the same chipset as the Citizen SR-59. What chipset it is, I have yet to find out; the machines I was able to open up had unmarked chips inside. Probably Toshiba.
Although the PSR-98 has conditional and unconditional branch instructions, its programming model is nevertheless somewhat simplistic. The most significant limitation is that jump destinations are limited to within nine steps of the current program location. There's also no ability to view or edit programs, making the programming process more cumbersome than it ought to be.
The programming example I wrote for this machine doesn't use branch instructions, however. It is a straightforward implementation of the logarithm of the Gamma function using the Lanczos-approximation. In addition to using 43 of the machine's 45 program steps, it also requires that you enter four constants into the calculator's memory registers; what you get in return is an algorithm that computes the result to 8+ digits of precision:
STO 3: 2.5066284644 STO 4: 41.41740453 STO 5: -27.063892494 STO 6: 2.2393179633 MS +/- - 3 . 1 5 + +/- ln × ( MR - . 5 ) + ( RCL 3 + RCL 4 ÷ MR + RCL 5 ÷ 1 M+ MR + RCL 6 ÷ 1 M+ MR ) ln =