Prinztronic Micro 8

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Calculators: Handheld: Prinztronic Micro 8

		Size (approx):	65mm x 116mm x 24mm (max) (w,h,d) Weight 70g excluding batteries
		Power:	9V DC, 1 x PP3 size battery, 0.2W. Does not accept an adapter. The on/off switch is located on the left side in line with the display.
		Case:	Main body is a u-shaped, stippled dark grey plastic section. The front consists of a matt/clear red plastic display filter and glossy buff-coloured keyboard surround, both of which sit slightly recessed to the edges. In the red plastic display filter is a black and blue printed metallic sticker, in its own recess, with the brand and model name. the small keys are short travel with a prominent plastic-sounding click on press and return.
		Display:	8 digit red LED with bubble lens, (no ninth digit)
		Features:	Standard four functions, two function memory and percentages.
		Age:	1976
		Manufacturer:	Not defined. Back panel only says Mini Calculator, made in Hong Kong.
		Comments:	Small palm-sized calculator that has the same construction methodology of many Rockwell models, even though the key colour scheme is more Commodore-like. The rather basic logic is not too bad but let down by seven digit negative numbers.

Components:	1 x cpu: Rockwell B5000CB 7607 (week 7 of 1976) 42 pin staggered DIL, 0.6" width black plastic with metal cap 1 x eight digit bubble lens LED (with nine bubble lenses) 7552 TIL 393-8, Korea 2 x resistors
Boards:	The keyboard board and the CPU board (Ref: PCB500362 A) are held in a two lug fixing post either side. They are tightly located together via 9 stiff wires.
Construction:	From the front, gently push away the sides until you can pop the lugs out from the keyboard surround. This panel and the display then falls off.

Logic comments:	(C/CE) is used to cancel the last number entered and a second press will clear the whole calculator.
	There is automatic constant on all four functions
	Input overflow is suppressed, keying a ninth digit is ignored
	Negative numbers are shown with a "-" sign the immediate left hand digit but as there is no ninth digit to go into it is limited to seven digit negative numbers
	Divide by zero shows "0.0.0.0.0.0.0." and is recoverable using (C/CE)
	Overflow is shown by the result and every decimal point alight and is recoverable using (C/CE)
	Memory storage is not indicated - you have to remember it