Detson 803PM

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Calculators: Handheld: Detson 803PM

		Size (approx):	72mm(max) x 123mm x 20mm(max) (w,h,d) Weight 102g excluding batteries
		Power:	3V DC, 2 x AA size rechargeable battery pack. It accepts an adapter/charger (3V 100ma 3.5mm plug centre positive) through a socket on the bottom side on the far right.
		Case:	Made from a two-piece gloss finish brown plastic case with rounded edges and corners. There is an oversized green display filter that gives a bright display. It contains a small metal label that is printed black with the company and model name and sits in its own recess. A brushed aluminium keyboard surround has the “on” label printed in black. The keys are small and squishy but work well.
		Display:	8 digit green VFD, with a ninth digit for negative, memory and error indication.
		Features:	Standard four functions with percentages, change sign, square root, pi and three function memory.
		Age:	197?
		Manufacturer:	Undefined manufacturer, made in Japan, serial No. 8652972
		Comments:	Compact calculator that is nice to hold with its smoothed edges but I'm not sure about brown. The logic is sound but the lack of recovery, missing constants and zero result for negative square roots could be better. The original case is soft black plastic with open top and half-moon cut-outs. Same design as the Decimo Vatman Mini M.

Components:	1 x cpu: NEC µPD278C H5Z076 (possibly 1976?) 28 pin DIL 0.6" wide 1 x 9 digit VFD with round face 1 x transistor 5 x diodes 6 x capacitors 7 x resistors 2 x resistor arrays 1 x transformer
Boards:	The keyboard assembly floats on top of the main cpu board and is held together with ten screws. It attached to the main cpu board via a 15-way ribbon cable.
Construction:	Very difficult to lever off the front as the lugs are on the rear section and this is very rigid. Front panel eventually lifts off. I would not recommend trying for fear of damaging the calculator.

Logic comments:	(C/CE) is used to once cancel the last number entered and a second time to clear the whole calculator.
	There is automatic constant on multiply and divide only
	Input overflow is suppressed, inputting a ninth digit is ignored
	Negative numbers are shown with a "-" in the far left (ninth) digit thereby allowing full eight-digit negative numbers
	Divide by zero shows "C” in the far left (ninth) digit and is not recoverable
	Overflow shows the result with "C" (or “E” if negative) in the left most (ninth) digit and is not recoverable
	The change sign can be used in mid-number entry
	Memory store is indicated by the decimal point of the far left (ninth) digit
	The (MRC) key is used once to recall the memory and a second time to clear it
	Negative square roots are not allowed and result in “C” with zero result