Lloytron Accumatic 55

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Calculators: Handheld: Lloytron Accumatic 55 (aka EH-8715)


	Size (approx):	90mm x 138mm x 23mm (w,h,d) Weight 162g excluding batteries
	Power:	6V DC using 4 x AA size batteries. It accepts an adapter/charger (DC 6V 250mW series 255A) through a socket on the top side to the far right. The on/off switch is also on the top side in the middle. A note on the back reminds you that you must remove standard batteries if using an adapter. Batteries were originally supplied with this model.
	Case:	Large calculator made from a three piece design; the rear is smooth black plastic, the sides are off white smooth plastic and the front section is matt black plastic. The two vertical edges are very rounded and bulge slightly. The neutral display filter is flat and flush but gives a clean bright image. It has printed white text with the model number. Below this a black printed metallic sticker sits in its own recess with the brand name. A slightly recessed brushed aluminium panel acts as a keyboard surround. They keys are soft touch, short travel and squishy but appear to work well. However, the contrast of black text on dark green keys does not work well for the higher functions.
	Display:	8 digit blue VFD with a ninth digit for negative, error and memory indicators
	Features:	Standard four functions with change sign, percentages, register exchange, square root, squares, reciprocal and five-function memory
	Age:	1975
	Manufacturer:	Lloyd's made in Japan, serial number 1-14980.
	Comments:	Sturdy feeling calculator that reduces the number of keys by having a two-key system for memory functions. Logic is OK with good error recovery but let down by negative square roots and fixed decimal bug. Same as the Lloyd's Accumatic 55 that was made in Taiwan The original case is soft black plastic with a top flip over flap that tucks in to a front band. It has Made in Japan embossed on the front.

Components:	1 x cpu; Rockwell A1241PA 7516 (week 16 of 1975), 42 pin staggered DIL, 0.6" width 1 x 9 digit VFD unit; single tube round faced 2 x transistor 9 x diodes 6 x capacitors 5 x resistors 2 x resistor arrays 1 x transformer
Boards:	The keyboard assembly (Gico GK128-11) floats on top of the main cpu board (801M 4) and is connected by 12 strong wires. The whole assembly sits loose in the calculator.
Construction:	Very difficult to open as this case is held together with internal lugs only - I do not recommend trying to open it for fear of damage. The easiest way I found was to use the coin slot on the top side to gently prize away the front of the case. Eventually the front section will lift off.

Logic comments:	(C) clears the last number entered on the first press and clears the whole calculator on the second
	Input overflow is suppressed, inputting a ninth digit is ignored
	There is automatic constant on multiply and divide only
	Negative numbers are shown by a minus sign in the far left (ninth) digit thereby allowing full eight digit negative numbers
	The change sign function can be used in mid number entry
	Divide by zero shows zero and a lower "o" in the far left (ninth) digit and is recoverable using (C)
	Overflow shows the result and a lower "o" in the far left (ninth) digit and is recoverable using (C)
	Memory store is indicated by the far left (ninth) digit decimal point
	Memory functions are two-key operations; use (M)(+), (M)(-), (M)(=) for recall, (M)(EX) for memory exchange
	The (EX) key used in isolation will exchange the calculators registers; i.e. (3)(÷)(9)(EX)(=) gives "3"
	Negative square roots are allowed and result in a negative number
	This calculator suffers the pseudo-fixed decimal bug; try (0)(.)(0)(0)(0)(+)(1)(=) gives "1.000" which remains fixed to three digits until an answer exceeds or multiply or divide is used.

	This scan shows the inside of the Lloyd's version which is exactly the same calculator with the front removed. Notice the main CPU IC with its typical Rockwell staggered pin configuration. Compare this to the insides of the Decimo Vatman X, it is very similar to this and other Gico using calculators.