Rockwell 14RD

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Calculators: Handheld: Rockwell 14RD

		Size (approx):	75mm (max) x 155mm x 25mm (max) (w,h,d) Weight 150g excluding batteries
		Power:	6.0V DC, 4xAA size batteries. Also accepts adapter (undefined) through top end socket on the left.
		Case:	Sturdy stippled brown plastic case with light beige keyboard surround. Neutral display cover shows a clear view of the numbers. Squashy but positive keys work well. The raised Rockwell logo and two vertical edges are painted silver.
		Display:	8 digit blue/green VFD with no ninth digit. The minus flag is a red LED on the top right corner.
		Features:	Four function plus percentages.
		Age:	1975
		Manufacturer:	Rockwell International, Microelectronic Product Division, Anaheim CA 92803. Serial No. 110562.046. I also have another with serial No, 116436.026, made in Japan.
		Comments:	Lovely typical Rockwell calculator with sound logic and clear display. Both the silver trim and any lettering on the keyboard surround have a tendency to rub off so finding good examples is not easy. Built to last - and they have. Original case is black plastic with flip top cover and tuck-in tab at the front. The red LED on mine has a habit of glowing after switch off for about 1/2 a second.

Components:	1 x cpu: A5911CA 7541 (week 41 of 1975) 42 pin DIL 1 x single glass tube, flat faced 8 digit VFD display plugs into socket 2 x transistors 5 x diodes 7 x resistors 6 x capacitors 1 x smoothing choke 2 x SIL resistor arrays 1 x 3mm red LED
Boards:	Keyboard board is attached to front by 12 screws and hinges to the main board on 14 stiff copper wires. Main CPU board is clip-fixed to the base. The main board has space for an extra transistor and LED - perhaps and overflow indicator.
Construction:	Remove the two small screws in the battery compartment. Gently push out the front keyboard which hinges up from the display surround. Pop off the display surround by using gently pushing a blunt object through the three slots on the rear.

Logic comments:	(CE) cancels an incorrect numerical entry, pressing a second time (C) clears the calculator
	Divide by zero shows "0.0.0.0.0.0.0.0." whilst overflows are shown with the answer and all points alight. The error is recoverable by use of (CE)
	Minus sign is shown by the red LED in the top right hand corner, thereby allowing eight digit negative numbers
	Input overflow is suppressed, typing in nine digits ignores the last one
	It has automatic constant on all functions