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Calculators: Handheld: Strand Memory (aka Decimo Strand Memory) (type I)
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| Size (approx): |
78mm
x 136mm x 15-23mm (w,h,d) Weight 122g excluding batteries. |
| Power: | 3.0V DC, 2 x AA size batteries. Also accepts adapter (undefined, 0.2W) through a right side socket roughly in line with the on/off switch. Battery life is quoted as 10 hours (manganese) and 20 hours (alkaline) approx. It was supplied with two batteries. |
| 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. There is a recessed area on the back for an owner's name sticker. |
| 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 |
| Age: | c1975 |
| Manufacturer: | Rear label says "Supplied exclusively by Decimo". Serial Number 4712779, 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. Switching on is a bit of a surprise as the digits are much higher (1cm from the top) than you would expect - and lop-sided. The logic is OK but let down by the lack of recovery. The original case is shaped 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. The calculator was originally supplied with its batteries and cover. The "manual" measures 65mm by 129mm and is just one sheet of two printed pages in black only. One side is specifications, the other is examples, in English only. No country of origin or reference numbers. See also Strand Memory type II. |
| Components: | 1 x cpu; NEC µPD278C H5Z816, 28
pin DIL, 0.6" width 1 x single round face glass tube 9-digit VFD 1 x transistor 7 x capacitors 6 x resistors 2 x resistor arrays 4 x diodes 1 x transformer |
| Boards: | The keyboard assembly floats loose on top of the main cpu board which is attached to the body with two pillars. They are joined via a 14-way ribbon cable and one wire. The display tube sits on its own board and is, in this case, mounted lop-sided. |
| Construction: | Remove the screw from the back (at the top) and gently lift off the front half hinging from the bottom. |
| Logic comments: | The Clear key (CE) will cancel last entry whilst the (C) key will clear the calculator completely |
| Overflow on the input of a number is suppressed - keying in a ninth digit is ignored | |
| There is automatic constant on multiply and divide only | |
| 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 | |
| Negative square roots are not allowed and result in zero and “C” in the far left (ninth) digit and is not recoverable |
