Prinztronic Mini

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Calculators: Handheld: Prinztronic Mini

		Size (approx):	55mm x 120mm x 12mm (max) (w,h,d) Weight 64g excluding batteries
		Power:	6.0V DC, 4 x AAA size batteries. Does not accept an adaptor.
		Case:	Two-piece light and dark blue smooth plastic case with light blue keyboard surround. Square, compact and slim but slightly squeaky design. It has an oversized red display filter that gives a reasonably bright display. Buttons are clear see though with a positive click. As the buttons float lose the whole thing rattles like a box of matches. A true pocket calculator.
		Display:	8 digit red bubble-lens LED with no ninth
		Features:	Four functions, with selectable constant and percentages
		Age:	1974
		Manufacturer:	Prinztronic (Dixons), made in Hong Kong. Serial No. 235146 on battery compartment cover and box.
		Comments:	One of the first striped down calculator achieving the price for the masses in the UK. Familiar design used for a number of variants. Original case is square shaped soft black plastic with flip over top. It tucks into a front pocket that cannot hold the manual. Basic but nice and can deal with very large and small numbers. Components are crammed in.

Components:	1 x cpu: Square geometric design, CL-590 7422 (week code 22 of 1974) 24 pin DIL 1 x display driver: ITT 7501J 7351 (week code 51 of 1973) 16 pin DIL 1 x 8 digit bubble lens red LED with additional full length magnifier; TIL395--8 7637 (date code week 37 1976) 0 x transistor 0 x diodes 1 x capacitors 0 x resistor arrays 8 x resistors 1 x transformer
Boards:	The keyboard assembly and main cpu board is one unit attached to the front via plastic rivets. There is a small display board.
Construction:	Gently push and twist a lever on the right hand side looking from the rear. Inside the battery compartment you will just see a fixing lug. About 2cm from the top and the bottom there are others on this side. By the time these two are popped you can do the top and bottom lugs and finally the three on the other side. Very difficult - do not try if you do not want to damage your calculator.

Logic comments:	(C) is used once to cancel the last number entered (and operator) and pressed again to clear the whole calculator.
	There is selectable constant on all four functions: i.e. (9)(X)(K)(3)(=) “27”, (5)(=) “45”
	Input overflow is suppressed, inputting a ninth digit is ignored
	Negative sign is shown in the eighth (far left) digit that would normally mean you are limited to seven digit negative numbers. However, this appears like some of the Sinclair Oxford calculators – able to work from 10^-20 up to 10⁷⁹ before resetting to zero.
	Divide by zero shows a single decimal point in the first digit and is not recoverable using
	It suffers the divide to negative zero bug: repeatedly dividing "-1" by "10" will result in "-0"


The box measures 135mm by 70mm and is 33mm deep. It is printed in two colours (blue and black) and has a sticker with the calculator's serial number.		The matching booklet measures 122m by 76mm and all internal pages are one colour black. It has an extensive 32 pages with plenty of examples and conversion charts too!