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Calculators: Handheld: Strand Memory (type II)
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| Size (approx): | 78mm
x 136mm x 15-23mm (w,h,d) Weight 124g excluding batteries. |
| Power: | 3.0V DC, 2 x AA size batteries. Also accepts adapter (undefined) through a right side socket roughly in line with the on/off switch. |
| Case: | The calculator is made from a glossy black and silver plastic case. The front is dominated by a wrap-around huge green plastic display filter. The latter has the brand name printed in white letters. The keyboard is surrounded by what looks like a painted plastic panel with reversed out text and red coloured label for some of the right hand keys. They keys are short travel with a positive loud click and work well on my example. |
| Display: | 8 digit green VFD with a ninth digit for minus, memory and error indicators |
| Features: | Basic four function with percentages, square root, change sign and three function memory. Switched constant facility. |
| Age: | c1975 |
| Manufacturer: | Rear label says "Supplied exclusively for W.H. Smith by Decimo". Serial number 4704221 made in Japan. |
| Comments: | Design that crops up on numerous calculators (see Same Calculators) but this one is odd as it mentions Decimo as the sub-supplier to W. H. Smith, a UK book and stationary store. However, on this type, the Decimo logo is missing from the front. The logic is quite good but let down by lack or recovery. Shaped case is black matt plastic, open topped with half-moon cut out and stiff back. It also has a cut-out at the bottom to let the air out as you slide the calculator in and is embossed with the word "Strand" on the front. Switching on is a bit of a surprise as the digits are much higher (1cm from the top) than you would expect. See also Strand Memory type I. |
| Components: | 1 x cpu; NEC µPD276C H53166, 28
pin DIL, 0.6" width black plastic 1 x 9 digit VFD unit, single tube round face 1 x transistor 9 x diodes 8 x capacitors 5 x resistors 3 x resistor arrays 1 x transformer |
| Boards: | The keyboard assembly floats loose on top of the main cpu board which is attached to the body with three pillars. They are joined via a 15-way ribbon cable and one wire. The display tube sits on its own board and is connected by another 19-way ribbon cable. |
| Construction: | Remove the screw from the back (at the top), loosen the power socket ring and gently lift off the front half hinging from the bottom. |
| Logic comments: | The Clear key (C) will cancel last entry whilst a second press will clear the calculator completely |
| Overflow on the input of a number is suppressed - keying in a ninth digit is ignored | |
| There is switched constant on all four functions | |
| The negative sign is shown in the far left (ninth) digit thereby allowing full eight digit negative numbers | |
| Divide by zero results in zero and "C" in the far left (ninth) digit and is not recoverable | |
| Overflow shows the result and "C" (or "E" if negative) in the far left (ninth) digit and is not recoverable | |
| The change sign function can be used in mid number entry but not before | |
| Memory store is indicated by the decimal point of the far left (ninth) digit | |
| The (M=) adds the result to the contents of the memory whilst (MR/C) is pressed twice to clear the memory | |
| Overflow in memory retains the original number | |
| Negative square roots are not allowed and result in zero and “C” in the far left (ninth) digit and is not recoverable |
