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Calculators: Handheld: Silver-Reed Mini IV
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Size (approx): | 70mm x
120mm x 20mm (max) (w,h,d) Weight 72g excluding batteries |
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Power: |
9.0V DC, 1 x PP3 size battery. Accepts an adapter/charger (200mW) through a socket on the top side, on the far left. | ||
| Case: | Compact little calculator made of black and white smooth plastic. A further black section surrounds the keyboard. The red display filter is very slightly angled but gives a clear display, despite the deep positioning of the LEDs. A mall brushed metal panel is printed black (lopsidedly) and sits in its own recess. Long travel squishy keys are subject to bounce on my example. The display filter has 9 digit numbers printed on it - despite only having eight functional digits! | ||
| Display: | 8 digit bubble lens red LED with no ninth digit despite the display inferring there is nine. | ||
| Features: | Standard four functions with percentages, change sign and four function memory | ||
| Age: | 1978 | ||
| Manufacturer: | Made in Hong Kong, serial number (in battery compartment) 153269. | ||
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Comments:
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Dainty calculator with a weird deep display. Nice prominent keys which have not survived well. It is let down by lack of error recovery and seven digit negative numbers. Original case is soft black plastic with open top and half moon cut-outs. It has the Silver-Reed words printed in silver. |
| Components: | 1 x cpu: TMS0972NL MBT 7840
Singapore (week code 40 of 1978), 28 pin DIL 1 x 8 digit LED display module with bubble lenses No other components |
| Boards: | The keyboard board is attached to the front by three screws. It joins the floating cpu board (Ref 830STM) via 11 strong copper wires. |
| Construction: | Difficult to open - do not try if you do not want to risk damaging your calculator. Squeeze in the rear panel at the top, you can then lever the back off by gently squeezing in to pop the other two side lugs and hinge off the at the bottom. |
| Logic comments: | The (C) key does not operate as a cancel entry function only to clear the calculator |
| Input overflow is suppressed, inputting an ninth digit is ignored | |
| Negative numbers are shown with a "-" in the immediate left digit but as there is no ninth digit you are limited to seven digit negative numbers. Typing in an eight digit number and using change sign will result in an overflow. | |
| There is automatic constant on all four functions | |
| The change sign function can be used in mid number entry | |
| Divide by zero shows "0." flashing and is not recoverable | |
| Overflow shows the result flashing and is not recoverable | |
| There is no indication of memory - you have to remember it |
