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Calculators: Handheld: Silver-Reed SR80
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Size (approx): | 85mm x
155mm x 36mm (max) (w,h,d) Weight 164g excluding batteries |
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Power: |
3.0V DC, 2 x AA size batteries. Accepts an adapter/charger (DC 3V, 300mW) through a socket on the top, on the far left. The battery compartment has a black ribbon to aid battery removal | ||
| Case: | Made from a two-piece smooth black plastic case with prominent brushed aluminium panels either side. The display is strongly tilted with a green plastic display filter that is inset. The patterned black plastic keyboard surround has individual raised areas for each key and an embossed label for the on/off switch. The small keys are reminiscent of Commodore keys, bouncy with a soft click. The lower sloping edge has a black printed metallic sticker with the brand and model name. A large instruction sticker on the back is in German only. | ||
| Display: | 8 digit green VFD with a ninth digit for negative and error indication | ||
| Features: | Standard four functions with percentages | ||
| Age: | 1975 | ||
| Manufacturer: | No manufacturing information given on the calculator, serial number 00007510. | ||
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Comments:
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More at home on the desktop, though it just about works as a hand-held calculator as well. Sturdy design with unnecessarily small keys and a display that lets in a bit too much ambient light. The logic is poor with no recovery, no display of overflow result and a host of various bugs. |
| Components: | 1 x cpu: Sharp LI2002 5F2 070
(date code June 1975) 28 pin DIL, 0.6" width white ceramic with black
cap 1 x 9 digit VFD unit, single glass tube, flat face: Itron FG95A LI 2 x transistors 7 x diodes 8 x capacitors 27 x resistors 1 x transformer |
| Boards: | The main cpu board (PCB500314) sits on top of the keyboard assembly (HM-20-10-RH 70036) and is held in place by two screws. They are joined by 15 blue, white red and black flying wires. The display is mounted on its own mini-board (PCB500281 REV A) that seems totally unnecessary. |
| Construction: | Remove the screw at the lower back and another within the battery compartment. The back section then lifts off easily. |
| Logic comments: | The (CE) key is used to cancel an entry whilst the (C) key clears the whole calculator |
| Input overflow is suppressed, keying in an ninth digit is ignored | |
| There is automatic constant on all multiply and divide only | |
| Overflow shows only "........0." and is not recoverable | |
| Divide by zero shows "........0." and is not recoverable | |
| Negative numbers are shown with a "-" in the far left (ninth) digit thereby allowing full eight digit negative numbers | |
| It suffers the negative zero bug: key in (1)(-)(2)(=) to give "-" then (+)(1)(=) to give "-0", it will also divide to negative zero | |
| It suffers the pseudo fixed decimal bug: key in (1)(+)(.)(0)(0)(0)(=) to give "1.000" which will remain a fixed three digit decimal number until more digits are required or you use multiply or divide |
