Sinclair Cambridge Memory

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Calculators: Handheld: Sinclair Cambridge Memory

		Size (approx):	50mm x 110mm x 19mm-24mm (max) (w,h,d) Weight 44g excluding batteries
		Power:	9V DC, 1 x PP3 size battery. It does not accept an adaptor/charger. The battery compartment is lined by a soft black plastic former.
		Case:	Two-piece smooth red plastic case which is designed so small that the 9V battery compartment protrudes out an extra 5mm! A raised escutcheon frames a deep purple display filter that gives quite a good, if narrow view of the digits. The keyboard surround is in contrasting black plastic. The white keys are short travel and give a prominent click but work well enough. The company and calculator name are printed in black text above the keyboard. Palm-sized calculator that can only be used in the hand and not on the desk due to the protruding back section.
		Display:	8 digit red LED with bubble lens with no ninth digit (discrete dot digits)
		Features:	Four functions plus percentages and five function memory.
		Age:	1976
		Manufacturer:	Sinclair Radionics of Cambridge, UK, made in England, serial No. (sticker in battery compartment) 703486.
		Comments:	A classic early pocket calculator from this British brand. Unusual red colour is an acquired taste. The logic is very good with full recovery and no major bugs - shame about the seven digit negative numbers. The display has nine digits but the first is never used. Note also that this uses the same IC as the Sinclair Cambridge Universal - but the extra functions are not accessible.

Components:	1 x cpu: Mostek MK50321N Malaysia 7622 (date code week 22 of 1976), 28 pin DIL, 0.6" width 1 x 9-digit miniature LED with bubble lens display Bowmar 3 x resistors
Boards:	One board that houses the keyboard assembly and main cpu assembly sits lose in the case. To minimise the thickness the display sits in a cut-out.
Construction:	Lugs hold the two sides together all around - three on the sides and one each top and bottom. High potential for damage trying to open it so beware. iF you must try, push ni the rear section on one of the side edges and work you way around.

Logic comments:	(C/CE) is used to clear once to the previous number entered and a second time to 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 "-" in the immediate left digit but as there is no ninth digit to travel into you are limited to seven digit negative numbers.
	Divide by zero shows a flashing "0." and is recoverable using (C/CE)
	Overflow shows the result flashing and is recoverable using (C/CE)
	Memory store is not indicated; you have to remember it
	Memory use is a two key sequence: (M)(+) to add to memory, (M)(-) to subtract, (M)(=) to recall, (M)(X) to exchange memory register and (M)(C/CE) to clear
	Overflow in memory stores the shifted result

The box measures 62mm by 125mm and is 31 mm deep - so not much bigger than the calculator itself. Printed in black only it is a double tuck-end construction.

"Made in England by Sinclair Radionics Ltd, London Road, St. Ives, Huntingdon, Cambs PE17 4HJ.

Use with PP3 9V battery (or equivalent)"

The manual supplied was a basic letter-sized sheet (273mm x 210mm) printed black on one side only in English and a reference number of 48584-320.

When supplied this calculator was given a 120 day guarantee, which seems a bit mean - and you had to pay the registered postage for return.