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Calculators: Handheld: Decimo Vatman (type 3)
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Size (approx): |
83mm
(max) x 132mm x 30mm (max) (w,h,d) |
| Power: | 6.0V DC, 4 x AA size batteries, 0.3W. Also accepts adaptor/charger (undefined though 3V centre positive worked fine) through a top side socket on the right. A sticker on back warns "Caution: never move the switch to "CH" position unless you replace the UM-3 batteries with the re-changeable nickel cadmium batteries." | ||
| Case: | Chunky two piece plastic case. Bottom is beige, top is matt black. Green display filter has painted logo. Decimo logo is metal inset panel. Keyboard surround is brushed aluminium. Top is slightly tilted upwards, including the back which causes the calculator to rock ,especially with no batteries to weigh it down. Top side three way switch is labelled CH for charge and ON. | ||
| Display: | 8 digit green VFD display with a ninth used for minus and error signs. | ||
| Features: | Basic four function with percentages, square root. | ||
| Age: | 1976 | ||
| Manufacturer: | Decimo Electronic Handy Calculator. Made in Japan. Serial No. 70101069. Also have 114668 | ||
| Comments: | Classic calculator which has a quality feel in the hand. Logic has a few issues. Imbalance on the desk and odd keyboard layout (why didn't they put the square root key down to make a complete square matrix keyboard?) let it down. Original black plastic case is top flap popper closing. For those non-UK viewers, VAT stands for Value Added Tax - the purchase tax system in the UK. |
| Components: | 1 x cpu; Hitachi HD37330 6C11
(March 1976), 28 pin DIL 0.6" width black plastic 1 x 9 digit VFD; single round faced tube 2 x transistors 5 x diodes 6 x capacitors 4 x resistors 0 x resistor arrays 1 x transformer: DCT-30 Zebra |
| Boards: | The keyboard assembly (HD37330 GK161-17.18) sits on top of the battery compartment and is attached to the main cpu (D-23-TC-0) board below with a 12 stiff wires. |
| Construction: | The front can be gently prized off after using the coin guide at the top. Squeeze the cream plastic sides so the lugs separate without breaking. |
| Logic comments: | The Clear Entry key (CE) is used to clear an input number, the clear (C) key is used to completely reset the calculator |
| Overflow on the input of a number is suppressed: keying a ninth digit is ignored | |
| The constant function is automatic on multiply and divide only | |
| The negative sign is shown on the far left (ninth) digit to allow 8-digit negative numbers | |
| A divide by zero or overflow error is shown by an "C" in the ninth digit and is not recoverable | |
| Negative square roots result in "E" in the ninth digit and is not recoverable | |
| It suffers the negative zero bug: (1)(-)(2)(+)(1)(=) gives "-0." | |
| It suffers the dive to negative zero bug: (1)(-)(=)(/)(1)(0)(=)(=)(=)... eventually gives "-0." |
