Commodore 897D

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Calculators: Handheld: Commodore 897D

		Size (approx):	75mm x 148mm x 25mm(max) (w,h,d) Weight 96g excluding batteries
		Power:	9V DC, using 1 x PP3 size battery. Does accept an adapter (605 or DC-620 3mm plug, centre positive) through a socket on the top side on the far right.
		Case:	Two piece matt plastic case in dark brown and beige. The keyboard surround is in matching dark brown whilst the panel below the display is black with a printed logo in white. Typical key colour scheme from Commodore and the small keys are very squishy but work well enough. The red plastic flat filter over the display is heavily inset so that the case forms a light screen. Display is very clear and large though rather limited in viewing angle.
		Display:	8 digit red LED with bubble lens with a ninth digit for negative, memory and error indication.
		Features:	Standard four functions, percentages, register exchange and four function memory.
		Age:	1976
		Manufacturer:	Commodore Business Machines Inc., Palo Alto, California, made in USA, serial No. 009890.
		Comments:	One of a large range, I think these wider models are much more attractive than the thin ones. The logic is very sound with good recovery and only let down by a lack of constant facility.

Components:	1 x cpu: Commodore 3D-98 2376 (week 23 of 1976), 22 pin DIL, 0.6" width 1 x 9 digit single unit bubble lens LED display
Boards:	The main CPU board (Ref: unreadable smudged red ink) is also the keyboard support and is held onto the front with 9 screws.
Construction:	Remove the two screws from the back of the case. Gently push the two lugs in the lower section cuts outs and squeeze off the back. There are two inner lugs that can be seen from within the battery compartment.

Logic comments:	(C/CE) is used once to cancel the last number entered and a second time to clear the whole calculator.
	There is no constant on any function
	Input overflow is suppressed, inputting an ninth digit is ignored
	Negative numbers are shown with a "-" in the immediate left hand digit travelling into the far left (ninth) to allow eight digit negative numbers.
	The (MR) key recalls the memory, the (MT) key exchanges the memory with the display value.
	Memory store is indicated by the far left (ninth) digit's decimal point
	It is possible to store an overflow in the memory and later recover it by continual division by 10
	Divide by zero shows "E00000000" (no decimal point) and is recoverable by dividing by one
	Overflow shows the result with "E" (negative or positive) in the left most (ninth) digit and is recoverable by continual division by 10 (or a multiple)
	(EX) is used to exchange the display with the register
	The (%) button divides by 100 so can also be used to recover from overflows

897D box

This calculator-sized box measures 80mm x 150mm x 27mm (H x W x D) and is printed in three colours with a "jazz-tech" image. This particular example has printed "model" and "Serial No." on the top flap but nothing else - I presume the sticker is missing. Made in the USA. Ref No. 300917.