Panasonic 885 JE-885U

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Calculators: Handheld: Panasonic JE-885U (885)


	Size (approx):	85mm x 145mm x 29-30mm (w,h,d) Weight 228g excluding batteries and strap
	Power:	6.0V DC, 4 x AA size batteries. It accepts an adapter (undefined, 6V DC, 0.5W) through a socket on the left side at the bottom. The battery compartment has a red ribbon to aid battery removal.
	Case:	It is built from a sturdy two-piece gloss white and matt light grey plastic case. Unusual thumb slot on the right with the brand printed in black text. A large matt black plastic keyboard surround has a raised recess for the model plate which is a black printed metallic sticker. The on/off switch has a silver coated plastic switch. The flush and ever so slightly tilted neutral display filter gives a clean bright image. There are faint labels printed inside the filter for digit numbers, negative and memory indicator reminders. A sturdy (and spinning) metal carry strap ring sits on the upper right hand side. The keys, which sit in their own recesses are soft, springy and rattle a bit but work very well on my example. There is a recess on the rear for a name sticker to be placed.
	Display:	8 digit blue VFD, with two discrete red LED for, memory and negative indication.
	Features:	4 function calculator with accumulating two function memory
	Age:	1974
	Manufacturer:	Matsushita Communication Industrial Co., Ltd. Made in Japan. Serial number on the inside of the battery compartment is 55500182
	Comments:	Well built heavy calculator with a quirky design but a nice large clear display. The logic is OK and let down by the negative zero bug. Quirky memory takes some getting used to as it is more usual for the memory light to flag non-zero contents rather than “memory on”. It is also difficult to get used to the (C) and (CE) keys being so far apart. The original case is soft black plastic with a top flap that attaches top the front with a Velcro tab. It is embossed with Panasonic Electronic Calculator on the front. One for everyone to have in their collection. Stuffed with components inside - marvellous!

Components:	1 x cpu; Matsushita MN5521 4E1 (date code 1 May 1974) , 28 pin DIL white ceramic package, 0.6" width 1 x 8 digit VFD unit, single tube round face 2 x Red LEDS 13 x transistors 11 x diodes 19 x capacitors 31 x resistor 2 x resistor arrays On power board: 1 x transistor 1 x diode 1 x capacitor 2 x resistor 1 x transformer
Boards:	There is a small power supply board situated in guides on the rear section of the calculator. The main cpu board (EC KP-8 4206 YLPRO000 3300) sits lose on top of the keyboard assembly and is joined by a 13-way ribbon cable.
Construction:	Remove the single screw from the rear section and the back will lift off easily.

Logic comments:	The (CE) button is used to clear last entry of a number and the (C) clear the whole calculator.
	Overflow on number input is suppressed inputting a ninth digit is ignored
	Negative numbers are shown with a red LED to the bottom left of the display thereby allowing full eight digit negative numbers.
	An overflow shows the result with a “ ’ ” to the top right of the digits. The number of tick marks tells you how many places to the right the overflow exceeds. Dividing by a multiple of ten allows you to recover the overflow. An overflow greater than 16 digits shows “EEEEEEEE” which is not recoverable.
	Divide by zero results in “EEEEEEEE” and is not recoverable
	There is automatic constant on multiply and divide only
	The memory is an auto-accumulation type. By pressing (M) you switch the memory on and a red LED lights to the bottom right of the display. When this is on the result of any equals key press is added to the memory. (RM/CM) will recall the contents of memory and then a second press will clear the memory – the light stays on as you are still in memory mode.
	This calculator suffers the negative zero bug. Try (1)(-)(2)(=) to give “-1” then add one with (+)(1)(=) to give “-0”