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Calculators: Handheld: Detson 808
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Size (approx): |
75mm
x 138mm x 20mm (w x h x d) |
| Power: | 9.0V DC using 1 x PP3 size battery. It accepts an adapter through a socket on the top side to the far right. There is a warning on the back stating “Do not use AC adaptor/charger when calculator is loaded with Alkaline battery [sic]”. | ||
| Case: | The case is two-piece smooth and matt black plastic, brick-shaped with rounded edges. A small black printed metallic sticker with the brand sits above the display in its own recess. Another similar sticker sits on the rear with the model number. The red plastic display filter is flat and flush, giving a bright but limited angle view of the digits. They keys are squishy and bouncy but work rather well. The keyboard has a brushed aluminium panel printed with black lines for effect. | ||
| Display: | 8 digit red LED with bubble lens but no ninth digit | ||
| Features: | Standard four functions with percentages and four-function memory. | ||
| Age: | 1977 | ||
| Manufacturer: | Detson, but with no manufacturing details except made in Singapore. Serial number 237637 is on the inside of the battery compartment. | ||
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Comments:
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This is one from a range of slim and functional calculators by Detson. It was obviously made as cheaply as possible. The logic is sound but let down by the limit of 7 digit negative numbers. Same case as the Detson 121. Minimal components on board to make it as cheap as possible. |
| Components: | 1 x cpu; TexasTMS0972NL KDS 7706
(week 6 of 1977), 28 pin DIL, 0.6" width 1 x 8 digit red LED display unit with bubble and linear lens 0 x transistors 0 x diodes 0 x capacitors 0 x resistors 0 x transformer |
| Boards: | The main cpu board (Bestek 14-0023) sits loosely above the keyboard assembly and is joined by a 13strong wires in the middle of the board! The latter is attached to the front with seven screws. |
| Construction: | Remove the two screws from the back. Gently lever out the bottom as this is the side that appear to pop the easiest. The serial number label keeps the top two sides joined so carefully hinge off the back from the top. |
| Logic comments: | The (CE) key is used to cancel an entry whilst the (C) key clears the whole calculator |
| Input overflow is suppressed inputting an ninth digit is ignored | |
| Negative numbers are shown with a "-” in the immediate left hand digit but as there is no ninth digit for it to travel into you are limited to 7 digit negative numbers. | |
| There is automatic constant on all four functions | |
| Divide
by zero shows a flashing "0." is recoverable using (CE) |
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| Overflow shows the result flashing and is recoverable using (CE) | |
| Negative square roots are allowed and result in a negative number | |
| There is no indication of memory store - you have to remember it! |
