Elektronika MK-85M
| 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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Elektronika MK-85M
The Elektronika MK-85/MK-85M are described as the last Soviet calculators ever made.
This programmable calculator very closely resembles similar calculators made by Casio. It is programmable in BASIC; the MK-85M provides 6 kilobytes of memory for programs and variables.
Like other Russian calculators that I had the good fortune to explore, the MK-85M is also a very slow device. Programs that execute in a fraction of a second on similar Western devices take several seconds on the MK-85M. However (as it was recently pointed out to me in an e-mail from Aleksandr Abrashkin) the MK-85M has a "fast mode". Holding down the + key while turning the calculator on causes it to run at several times normal speed, albeit at a greatly increased power consumption. Curiously, the same feature is absent in the MK-85M's smaller cousin, the MK-85.
A curious feature of the MK-85M is its ability to address display pixels individually, making it possible to produce some crude graphics. The calculator also has an extensive character set, including both Cyrillic letters (upper- and lowercase) and graphical symbols. Another unusual feature is the undocumented WHO command.
More information about the fascinating history of the MK-85 family is available at http://www.computer-museum.ru/histussr/mk_85_1.htm.
The following implementation of the Gamma function demonstrates programming on the MK-85M:
100 INPUT "X=",X 110 T=1 120 IF X>=0 THEN 160 130 T=T*X 140 X=X+1 150 GOTO 120 160 G=1.00000000019 170 G=G+76.1800917295/(X+1) 180 G=G-86.5053203294/(X+2) 190 G=G+24.0140982408/(X+3) 200 G=G-1.23173957245/(X+4) 210 G=G+1.20865097387E-3/(X+5) 220 G=G-5.39523938495E-6/(X+6) 230 G=LN (SQR (2*π)*G/X) 240 G=G-X-5.5+LN (X+5.5)*(X+.5) 250 PRINT EXP(G)/T
