Casio fx-31

 

Calculator Casio fx-31 Comments: Fabulous quality calculator from a famous range only missing fractions. As they got it so right, this layout remained for years - well into LCD calculators. Displays sexagesimal with a "°" symbol. Sound logic but limited mantissa, basic memory and lack of error recovery. Original case is soft black plastic with open top and half-moon cut-outs either side. It has Casio embossed on the front and Made in Japan on the back. Size: 84 x 145 x 24.6 by 132g excluding batteries Power: 3.0V DC, 2 x AA size batteries, 0.25W. Accepts adaptor AD-2S through a socket on the top side to the far left. Battery life is quoted at 24h alkaline continuous operation. The on/off switch is on the left hand side, just above the display.

Logic comments: The Clear key [C] is used to clear an input number, the all-clear [AC] to completely reset the calculator (which does not clear the memory). Overflow on the input of a number is suppressed, typing in a ninth digit is ignored The constant function is invoked for all four functions by a double press of the operator: i.e. [3][X][X][4)[=]  “12” [=]  “36” etc. There ere is no

indication of memory use - you have to remember it, an and d us usin ing g th the e [Min]  key will ove overwr rwrite ite a pre previo viousl uslyy stored number Negative numbers are shown with a “-“ to the immediate left of a number, travelling into the far left left (nin (ninth th)) digi digitt to allo allow w fu fullll eigh eightt digi digitt nega negati tive ve numbers On overflow the display just shows "E" in the far right (first) digit and is not recoverable On divide by zero the display just shows " E" in the far right (first) digit and is not recoverable If you try to use more than 6 levels of parenthesis, or functions the display just shows “C” in the far right (first) digit and is not recoverable Negative square roots are not allowed and result in an error as above The change sign function can be used in mid number entry There is no recovery from any type of error There is a small exponent display bug: key in the

Case:  Smooth plastic white base and dark blue top. Above the display is a full-width wrap around metallic sticker, in its own recess, printed black and blue with the brand and model number. A neutral and slightly tilted tilted plastic plastic display display filter filter gives gives a clean clean ima image. ge. The brushed aluminium keyboard surround is also recessed and printed black, blue and brown with key functions. Typ ypic ical al Casi Casio o keys keys are are squi squish shyy but but posi positi tive ve with with 12345678 [EXP]  whic n123456 umber 0.0   th thean n erroneous which h wi willll point disp display lay individual plastic escutcheons. “ ” showing decimal in Display: 8 digit blue VFD with a ninth digit for negative the exponent exponent until until you press equals You can ent enter er indication and scientific mode display degrees, minutes, seconds using the [° ' ''] key, which it displays in decimal form. To see it in DMS form use the Components:  1 x cpu: Hitachi HD38111A 8F13 keys [INV][