Brother 408AD

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Calculators: Handheld: Brother 408AD

		Size (approx):	78mm x 142mm x 15-20mm (w,h,d) Weight 120g excluding batteries
		Power:	3.0V DC, 2 x AA size batteries. Accepts an adapter (DC-320RA, DC-320E or DC-315P, 3V 0.25W) through socket on the top side on the far left.
		Case:	The case is two matt black plastic with a wrap around brushed aluminium facia. This is printed in black to reverse out the key labels, company name and model number. An inset green display filter gives an easily viewed and bight display. Two flashy raised plastic stripes separate the flat upper area from the wedge shaped lower two thirds. Solid and heavy with a slight squeak to the case. The oval keys are long travel soft touch but work very well.
		Display:	8 digit green VFD display with a ninth digit for negative and error signs.
		Features:	Standard four functions with percentages, square root, pi and change sign.
		Age:	c1976
		Manufacturer:	Brother Industries Ltd, made in Japan, serial No. D6158856
		Comments:	Attractive, solid calculator with the UK Brother company name. Lack of a memory is odd along with the lack of nine digit input suppression missing. If you add the error of allowing negative numbers then this is a shaky calculator. The original case is soft black plastic with an open top and half-moon cut-outs and is slightly too small.

Components:	1 x 9-digit flat faced VFD display unit Itron F695A JC I 1 x cpu NEC µPD940C R61106 2 x transistors 10 x diodes 5 x resistors 4 x resistor arrays 7 x capacitors 1 X transformer
Boards:	The keyboard assembly (BP-2177-1) is fixed to the front section with a single screw and attached to the main board via a short 10-way ribbon connector. The mina board sits lightly held in the rear section by two of the battery connectors. It has board ID BP-2176-1.
Construction:	Whilst the case has two "lever points" I found it easier to pop the top one then the top edge and back down the other side. The bottom popper is quite tight, so be very careful. Eventually the top section hinges away from the lower end.

Logic comments:	The (CE) key operates as a cancel entry function whilst the (C) key clears the calculator
	Input overflow is not suppressed, inputting a ninth digit results in "C" (or "E" if negative) in the ninth (far left) digit
	Negative numbers are shown with a "-" in the immediate left hand digit travelling into the ninth digit thereby allowing eight digit negative numbers.
	There is automatic constant on all four functions
	Divide by zero shows an "E" in the ninth (far left) digit and is not recoverable
	Overflow displays the result and "C" (or "E" for negative overflows) in the ninth (far left) digit and is not recoverable
	The change sign key can be used in mid entry of a number
	Negative square roots are allowed

The box shown on the left measures 90mm x 168mm x 35 mm and is printed in yellow and black. On one end the model number is printed on as 408AD with the "A" stamped on. A serial number sticker matches the calculator. Made in Japan.