Casio AL-8

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Calculators: Handheld: Casio AL-8


	Size (approx):	82mm x 140mm x 25mm (w,h,d) Weight 175g including batteries.
	Power:	3.0V DC, 2xAA size, 0.2W. Also accepts adapter (AD-2S) through a socket on the top side to the far left. Alkaline batteries give about 20 hours continuous use, manganese dry about 10 hours. The on/off switch is on the left hand side in line with the word Casio.
	Case:	Three piece smooth plastic case with base in burgundy, top in white and a third front piece in burgundy. The neutral, slightly tilted display filter gives a clear image. A small brushed aluminium panel at the top has black and blue printed text for the make and model number. A similar panel surrounds the keyboard with black text for some key labels. The keys are the typical squishy Casio ones that work rather well.
	Display:	8 digit blue VFD with no ninth digit.
	Features:	Standard four functions with percentages, square root, automatic accumulation (grand total), remainder, fractions, hms/dms, stats functions and four function memory. Full floating, cut-off or round-off at two decimal places.
	Age:	1976
	Manufacturer:	Casio Computer Co. Ltd. Made in Japan. Serial number 1396753 on sticker inside battery compartment.
	Comments:	The first calculator to handle fractions and sexagesimal numbers easily. Unusual "function" key (the "P" key") is set with a sliding switch. Handy reminder panel on back. There was a later AL-8S that replaced the sliding switch with individual buttons and added a date function but dropped the HMS and stats functions. Sound logic except for negative square roots and lack of an ninth digit.

Components:	1 x cpu: NEC D573C R66635, 28 pin DIL, 0.6" width 1 x 8 digit VFD; single tube round face 2 x transistor 14 x diodes 9 x capacitors 5 x resistors 1 x transformer;7C2 CD1201 TDK
Boards:	Main board (D8R-1A) is connected by 19 copper wires to the (and sits on top of the) keyboard board. The latter is secured to the front by 6 screws. There is a small piggy back board module with the transformer and associated components.
Construction:	Remove the single screw from the inside of the battery compartment. Pop the lug that is visible just to the left of this, then the lower on on this side. One more on the other side and the back lifts off. Quite difficult to do without causing damage.

Logic comments:	The (C) button is used to clear last entry of a number and (AC) to clear the whole calculator.
	Overflow on number input is suppressed, keying in a ninth digit is ignored
	There is selectable automatic constant on all multiply and divide only by double hitting the operator; i.e. (3)(X)(X)(=) gives "9".
	An overflow error is flagged with an "E" in the first (right most) digit, negative or positive and is not recoverable.
	Divide by zero shows an "E" which is also not recoverable.
	A round off switch and fixed two-decimal point notation is available.
	Square roots of negative numbers are allowed and result in a negative zero bug; Continuously square root -1.01 until it reads "-1" then (+)(1)(=) results in "-0"
	There is no indication of memory store - you have to remember it.
	Higher functions are selectable with a sliding switch changing the function of the (P) key.
	Fractions are separated by a inverted lower "L" and sexagesimal notation by an upper "o"
	Negative numbers are flagged by a "-" sign in the immediate left digit, limiting you to seven digit negative numbers. If you type in (-)(1)(2)...(8)(=), this will result in an error.

This original manual is approximately 105mm x 74mm, 28pp. It clearly shows the representation of fractions, which was to be used for many years by Casio calculators. Printed in Japan but no reference numbers or date.