Casio FX-17

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Calculators: Handheld: Casio FX-17

		Size (approx):	90mm x 150mm x 30mm (max) (w,h,d) Weight 176g excluding batteries
		Power:	6V DC, 4 x AA size batteries. It accepts an adapter (6V DC 0.33W, type AD-4145) through socket on the top side to the left.
		Case:	Quite a bulky model made from a two-piece glossy white and matt light grey plastic case. A neutral plastic display filter is tilted and sits in its own raised section. The rest of the front is taken up by a flush metallic panel printed in dark brown and blue, doubling as the keyboard surround. The keys are medium length travel and very bouncy with a soft click on return.
		Display:	8 digit blue VFD with a ninth digit for negative indication, small zero display (see below).
		Features:	Standard four functions with squares, square root, pi, sexagesimal input (not display), change sign, reciprocal, trigonometric and transcendental functions including powers. Four function memory. Standard or 5+2 scientific display modes.
		Age:	1976
		Manufacturer:	Casio Computer Co., Ltd., made in Japan, serial number 5470196 on a sticker inside the compartment.
		Comments:	Big chunky early calculator that just fits in the hand and has the classic FX key layout. The logic is bug-free but has limited precision (especially on logs), limited exponent, sloppy powers and no recovery at all from errors. The original case is soft black plastic with double top flap with popper closing. It has Casio embossed on the front and Made in Japan on the back.

Components:	1x cpu: Hitachi HD37678B 6D11 (date code April 1976), 28 pin DIL, 0.6" width black plastic 1 x 9 digit VFD: single tube round front face: (date coded 6D as well) 0 x transistors 0 x diodes 8 x capacitors 3 x resistors 3 x resistor arrays 1 x power supply unit: Fuji UT0644 PAT No. 427559 6D-14
Boards:	The main cpu board (C8R-1A) sits face down on the keyboard assembly (A8Y-E4B) held in place by plastic ledges/posts and the 14 stiff interconnecting wires. The keyboard is attached to the front with seven screws.
Construction:	Remove the screw from within the battery compartment. This does not really help as the case is held together by internal lugs. The easiest way I found was to push in the front section side on a side top edge and pop the lug. After popping the side and bottom lugs, hinge from the top. Be very careful as damage can easily result. Eventually the back will lift off.

Logic comments:	(C) is used to cancel the last number entered and (AC) to clear the whole calculator
	There is selectable constant on multiply and divide only by double-hitting the operator: i.e. (X)(X)
	Input overflow is suppressed, inputting a ninth digit is ignored
	If you key in more than six digits you cannot enter an exponent
	Negative numbers are represented by a “-“ to the immediate left of the number travelling into the far left (ninth) digit thereby allowing full eight digit negative numbers
	Overflow shows only “E” in the far right (first) digit and is not recoverable
	Divide by zero shows only “E” in the far right (first) digit and is not recoverable
	Square roots of negative numbers are not allowed and result in “E” in the far right (first) digit and is not recoverable
	Transcendental (logs) and trigonometric results are limited to five and occasionally six decimal places respectively
	You can input sexagesimal number formats using (° ' ")but they are displayed as a decimal number only
	Power raising shows the intermediate step of using a log so that (2)(X^y) shows "0.6931474" then (8)(=) gives "256". Interestingly this is one digit of precision more than if you used the (ln) key
	There is no indication of memory store - you have to remember it!
	Scientific display is limited between 10³⁹ and 10^-39
	Overflow in memory is flagged and retains the original number
	No other bugs found

This image shows the small zero notation of the display. I believe that this format was invented so that if any one segment was out you could still tell what the number was. This idea wasn't to survive past 1975 though.