Binatone 02-4252

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Calculators: Handheld: Binatone 02-4252


		Size (approx):	80mm x 145mm x 28mm (max) (w,h,d) Weight 154g excluding batteries.
		Power:	6.0V DC, 4 x AA size batteries. Also accepts adapter (undefined) through socket on the top side to the far left.
		Case:	Two-piece matt plastic case in dark and light blue. The upper area has a fake grill -like design just like old desktops that needed cooling slots. Below this is a black printed metallic sticker with the brand name. A raised, flat, neutral plastic display filter has a silver painted escutcheon. The keyboard surround is recessed and consists of a silver painted panel with the on switch label embossed. The keys are large, with a short travel action and loud positive click (Klixon type).
		Display:	8 digit green VFD with a ninth digit for negative and error indication and display power down indication
		Features:	Basic four function with percentages and display power save
		Age:	1975
		Manufacturer:	No credit given, made in Singapore, serial number 015463. The inside of the battery compartment has what looks like a QA stamp with "Unico QC K Set 8".
		Comments:	Chunky calculator with nice colour scheme, easy to use keys and clear display. The logic is fair with good recovery and only let down by the pseudo fixed decimal bug. The original case is thin black plastic with flip over top and front Velcro pad fastening. Appears to be the same as the Eltex 2000 calculator from Germany.

Components:	1 x IC: Texas TMS0851NL 7541 (week 41 of 1975), 28 pin DIL, 0.6" width 1 x 9 digit VFD module: single glass tube flat face: Itron FG95A IJ 2 x transistors 3 x diodes 5 x capacitors 21 x resistors 0 x resistor array 1 x transformer: 034 019 Sumida
Boards:	The main cpu board is attached to the rear with three screws whilst the keyboard (ETCO E3330A-47 REV-C) is attached to the front with two metal brackets screwed in place. The are connected by 15 short insulated wires.
Construction:	Remove the two screws from the rear of the case and then the two from within the battery compartment. The two halves will separate but not very much as they are held together by the connecting wires.

Logic comments:	(C/CE) cancels the last number entered whilst a second press will clear the whole calculator
	Input overflow is suppressed; inputting a ninth digit is ignored
	There is automatic constant on all four functions
	Negative numbers are represented by a "-" sign in the immediate left hand digit. This can travel into the far left (ninth) digit thereby allowing full eight digit negative numbers.
	Overflow shows the result and "C" (or "E" if negative) in the far left (ninth) digit and is recoverable using (C/CE)
	Divide by zero results in zero and "C" in the far left (ninth) digit and is recoverable using (C/CE)
	After six seconds the display goes into power save mode with only the "-" of the far left (ninth) digit showing, recovery is by use of the (D) display key
	It suffers the pseudo fixed decimal bug: key in (1)(+)(.)(0)(0)(0)(=) to give "1.000" which will remain a fixed three digit decimal number until more are needed or you use multiply or divide

The box measures approximately 162mm by 90mm and is 35mm deep. At this size it just about fits the calculator in its case, so nothing else came with it.

It is printed in Green, blue and black with the serial number stamped on the right hand end. This image is the lid which hinges off the top edge. The Binatone logo and model number is a sticker, which isn't quite the same colour. This usually means it was a generic model branded by other companies.