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Calculators: Desktop: Casio JE-3

Size (actual): 108.1mm x 145.1mm x 20.1mm(max)  (w,h,d)
Weight 134g excluding batteries

Power:

3V DC, 2 x AA size battery, 0.3W.  Also accepts adaptor (AD-2S, 3V centre negative).  Socket on top side on the mid left.
Case: Square compact desk-top design which slightly slopes upward.  The display slopes out at about 40 degrees making it quite prominent and perfect for use on the desk.  It is made from a two-piece matt and gloss black plastic case.  A large brushed aluminium panel surrounds the keys with some black text labels.  The large keys in orange, grey and blue are typical squishy, short travel Casio buttons with their own escutcheons and have a soft click.  The neutral display filter gives a fairly low contrast display and has printed text on the underside in white and orange.
Display: 12 digit green backlight reversed LCD with left symbol cluster for error, memory, constant and negative indicators, right cluster for operator indication and four top bars for mode indication.
Features: 4 function calculator with percentages, backspace, change sign, square root and four function memory.  Floating, and rounded fixed decimal, grand total, rounding. Key on/off function. Reset button on the rear.
Age: c1989-1993
Manufacturer: Casio Computer Corp.  Made in Japan.  There is a number printed on the inside of the battery compartment that may be a serial number or a part number: 8H102A. 
Comments:

 

A quality feeling calculator that I'm tempted to use on my desk today except for the rather dim experimental display.  I can only guess that the "business market" that this was aimed at were those people unhappy with the loss of nice bright VFD digits. Very sound logic. The vast majority (if not all) of the components in this calculator are to light the display.

Components: 1 x cpu: Unmarked Surface mount 40 pin (20mm x 14mm) 
1 x display: 12 Digit LCD with (VFD?) electro-luminescent backlight panel.
5 x transistor (SMT)
0 x diodes
3 x capacitors (SMT)
3 x capacitors (through hole)
8 x resistors (SMT)
1 x transformer; E11601 E8112
Boards: The double-sided Surface Mount Technology board (V210-1 A310253-1) is fixed to the front of the case with three screws. The keyboard is an integral part of the reverse side.  The display is connected via a 42-way ribbon cable and three transformer wires. 
Construction: Remove the three screws from the base.  There are three lugs on the top edge and two on the bottom that will need to be gently prised away - which then will allow the rear section to lift off. 

Logic comments: (C)  is used to clear last entry of a number and (AC) to clear the whole calculator (and switches it on)
Overflow on number input is suppressed, keying a thirteenth digit is ignored - digits can be deleted by using backspace (>) key
The backspace key (>) can also be used to erase digits from answers
An overflow error results in the number and an "E" in the symbol cluster to the far left and is recoverable using (C)
Divide by zero results in a  "E" as above and is not recoverable.
There is selected constant on all four functions by double keying the operator, a "K" is shown in the symbol cluster to the far left
When ever you key in one of the four functions, a symbol lights up in the far right symbol cluster
Square roots of negative numbers are not allowed but show the result and "E" which is recoverable using (C)
Memory store is indicated by an "M" in the symbol cluster to the far left
Overflow in memory is flagged and maintains the original number
Negative numbers are indicated by a "-" in immediate left digit, travelling into the symbol cluster to allow full 12 digit negative numbers
There is a decimal switch for floating (F), round down (CUT), round (5/4), the last two being fixed two digit decimal mode - a small top bar lights on the right to remind you of the mode
(GT) is the Grand Total, the result of adding every previous result since (AC) was used, a small top bar light up on the left when GT <>0
You can change sign during a number entry but not before
Percentage marks up can be achieved just by hitting the (+) key
No bugs found