Decimo Super Vatman type V

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Calculators: Handheld: Decimo Super Vatman (type v)


		Size (approx):	83mm (max) x 132mm x 30mm (max) (w,h,d) Weight 148g excluding batteries
		Power:	6.0V DC, 4 x AA size batteries. Also accepts adapter/charger (6V, 0.3W, 3.5mm centre positive) through a top side socket on the right. The switch is a three-position on/off/charge selector. Takes regular alkaline or rechargeable batteries. A sticker on the back states that dry cell batteries must be removed if you switch to charge mode whilst using an adapter. There is a power save function after about 30 seconds that switches off the display.
		Case:	Chunky two piece plastic case. The bottom section is light grey, top is matt black. An oversized green display filter, which is flat and almost flush, has a white printed model name and gives a bright display. The Decimo logo is black printed metallic panel that sits in its own recess. The 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. The keys are soft and squishy but work well enough.
		Display:	8 digit green VFD display – with a ninth right hand symbol cluster (o/-/M) used for negative, memory and overflow indicators
		Features:	Standard four function with percentages, square root, squares, reciprocal and four-function memory
		Age:	1976
		Manufacturer:	Not mentioned, Electronic Handy Calculator, made in Japan. Serial No. 602 59858
		Comments:	Classic calculator that has a quality feel in the hand. Imbalance on the desk is odd. For those non-UK viewers, VAT stands for Value Added Tax - the purchase tax system in the UK. The logic is fairly solid with good recovery but and odd continuous overflow system and negative roots. Oddly enough the IC it uses is also in the Super Vatman type iv - with a key system that is totally different from this one. It also appears to be very similar to the Elite S 2003.

Components:	1 x cpu; NEC µPD946C R5Z826 28 pin DIL, 0.6" width black plastic 1 x 8 digit plus symbol cluster VFD; single tube round face 2 x transistors 4 x diodes 7 x capacitors 11 x resistors 1 x resistor arrays 1 x transformer: DCT10B
Boards:	The keyboard assembly (G946C 4004MR GK251-9 and a GICO 51.1.19 sticker) sits on top of the battery compartment and is attached to the main cpu board (EL-404B) below with a 15-way ribbon cable. The Gico sticker is the 19th January 1976.
Construction:	The front can be gently prized off after using the coin guide at the top. Squeeze the grey plastic sides so the lugs separate without breaking and then hinge from the bottom. You do not need to remove the three screws in the battery compartment as they hold the assembly to the back.

Logic comments:	The Clear Entry key (CE) is used to clear an input number, and a second clear key (C) to completely reset the calculator
	Overflow on the input of a number is not suppressed - typing in nine digits results in overflow. "^o" is shown in the ninth (far right) symbol cluster and is recoverable by dividing by a multiple of ten
	The constant function is automatic on all four functions
	Overflow shows the result and "^o" in the ninth (far right) symbol cluster and is recoverable by dividing by a multiple of ten. You actually can continue to calculate with up to 16 digit numbers when the display shows zero.
	A divide by zero shows "0." and "^o" in the ninth (far right) symbol cluster and is not recoverable.
	The negative sign is shown in the ninth (far right) symbol cluster thereby allowing full eight digit negative numbers.
	Memory store is flagged by the display of "_M" in the ninth (far right) symbol cluster
	The memory is cancelled by double pressing the (RM) key
	Negative square roots are allowed and result in a negative number
	The power save function switches off the main display after 27 seconds with just the middle horizontal segment of the first digit alight.

	As in all this type of Vatman range, the components are crammed into the top area of the body. There are even a few components under the display tube. You can just make out the symbol cluster on the far right of the display tube. Compare this with the Elite S 2003.