Hanimex VP8

		Home New Stuff Author Links Guest book Web-log	Adverts Bric-a-brac Calculators Components Ephemera Events	For Sale Glossary History Hit or Miss Radios Transport	Ultra Valves Wanted Metal Puzzles Clocks

Calculators: Handheld: Hanimex VP8

		Size (approx):	58mm x 112mm x 16mm (w x h x d) Weight 64g excluding batteries.
		Power:	3.0V DC using 2 x AA size batteries. It accepts an adapter (undefined) through a socket on the top side to the right. The on/off switch is on the right side in line with the display.
		Case:	Very small case made of three-piece brown and beige plastic. The very slight raised and flat red plastic display filter gives a soft image with good angle of view. This filter has white printed text for the brand. Below this some designer lines frame a green printed black plastic label that sits in its own recess and shows the model number. The keyboard surround is a matching beige plastic panel and the keys are short travel with a positive click.
		Display:	8 digit red LED (multi-dot flat type) with a ninth digit (I think) for negative and error indication.
		Features:	Standard four functions with percentages,
		Age:	1975
		Manufacturer:	Made in Hong Kong, serial number 51104643 is on a sticker inside the battery compartment
		Comments:	Very compact palm sized basic calculator. Reminiscent of some Prinztronic models but very similar to the Continental. The ninth digit appears to be not working on my example so some of the logic comments are educated guesses. The logic is good, only let down by the pseudo fixed decimal bug and divide-negative zero bug.

Components:	1 x cpu; Square spiral CF 593 7539 (week 39 of 1975), 28 pin DIL, 0.6" width black plastic 1 x 9 digit red LED unit: Bowmar Optostic 2M2 R7H-122-9 10 x transistors 2 x diodes 2 x capacitors 12 x resistors 1 x transformer
Boards:	The whole inside assembly sits loose. The main cpu board is attached to the keyboard assembly by a 13-way connector.
Construction:	Six internal lugs hold the whole case together. The best way to open it, I found, was to use a fingernail to prize away the front of the case. Very difficult so if in doubt do not attempt as damage may result.

Logic comments:	The (CE) key is used to cancel an entry whilst the (C) key clears the whole calculator
	Input overflow is suppressed inputting a ninth digit is ignored
	Negative numbers are shown with a "-” in the immediate left digit, travelling into the far left (ninth) digit thereby allowing full eight digit negative numbers.
	There is automatic constant on all four functions
	Overflow shows the result and “C” (or “E” if negative) in the far left (ninth) digit and is recoverable using (CE)
	Divide by zero shows zero and “C” in the far left (ninth) digit and is recoverable using (CE)
	It has the pseudo fixed decimal bug: key in (1)(+)(.)(0)(0)(0)(=) to get "1.000" which remains a fixed three digit number until more digits are required or you use multiply or divide.
	It has the divide negative zero bug: key in (1)(-)(2)(=) to give "-1" then continually divide by 10 until you get "-0"

	This scan shows the inside assembly of the calculator. Note the large number of transistors to drive the display - a sign of an early 1970s pocket calculator. This really is an ingenious cram! the whole board is not much bigger than the nnnnn IC. Notice also the spare holes suggesting that this board was to be used for several different models. Compare this with the Continental inside {which opens another window with the image}. This one appears to be missing the extra transistor to drive the ninth digit.