Binatone Cadet

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Calculators: Handheld: Binatone Cadet (aka model 02-4694)


		Size (approx):	72mm (max) x 125mm x 18mm (max) (w,h,d) Weight 92g excluding batteries.
		Power:	3.0V DC, 2 x AA size batteries. Also accepts adapter/charger (4.5V DC max, 3.0V DC, 300mA) through a top side socket to the far right. A warning note on the back states that "Alkaline battery must not be used with AC adaptor". Ni-Cad batteries that are in the calculator are charged simultaneously when operating from an AC adapter.
		Case:	Made from a matt black plastic front and smooth light grey plastic rear. The upper panel is printed with white text for the brand and model name. It also has digit numbers and sign ID running along the top of the display. The flat and flush neutral plastic display filter gives an OK image. They keys are short travel with a loud click but work well enough. They do, however, rotate as the key holes are a little too big.
		Display:	8 digit green VFD with a ninth digit for negative, memory and error indication.
		Features:	Basic four function with percentages, change sign and four-function memory.
		Age:	1975
		Manufacturer:	Undefined with no country of origin on the calculator or manual. Serial number 626647 on a sticker inside the battery compartment.
		Comments:	Futuristic design that looks very smart indeed, unfortunately the matt black panels at the front scuff very easily. The logic is OK but let down by lack of recovery and odd two/one key memory system. The original cover is brown soft plastic with open top and half-moon cut-outs either side. Similar design to the Hanimex BCM368.

Components:	1 x IC: Mostek MK5022AN 7527T (week 27 of 1975), 28 pin DIL, 0.6" width 1 x 9 digit VFD module: NEC LD8118 2 x transistors 5 x diodes 6 x capacitors 4 x resistors 1 x resistor array 1 x transformer: H05 740 Sumida
Boards:	The main board (SPL-0038) sits face down on top of the keyboard assembly which is fixed to the front. They are joined by 15 strong, bent wires.
Construction:	Very difficult to open as this is held together by internal lugs only and the sides are so stiff and tight fitting that damage is very likely to result. If you really must try, I found the best way was to push gently out the top edge of the rear section and prize apart with a fingernail. I would not recommend it. The rear section will eventually lift off.

Logic comments:	(C) 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 "ⁿ" in the far left (ninth) digit and is not recoverable
	Divide by zero results in zero and "ⁿ" in the far left (ninth) digit and is not recoverable
	Memory store is indicated by a "_L" in the far left (ninth) digit
	Memory use is often by a two key operation: (M)(+) to add to memory, (M)(-) to subtract to memory, (M)(C) to clear memory, but oddly enough just (MR) to recall.
	The percentage key just divides by one hundred, once only
	Overflow in the memory wipes the contents after recovery using (C)
	No major bugs found.

The manual measures 116mm by 69mm and is 16 pages in total. Whilst the cover is black and white, the insides are printed in blue and white. I can see why they called it the Cadet as the model number doesn't exactly roll off the tongue!

Some good examples and even space for your own notes. However, there is no origination information.