Casio fx-3800P scientific pocket calculator

Made in mid 80's.
No way to know for sure as there are no date codes in any internal component.

Forensics result as displayed: 9.000015718
(Degrees mode. 9 sin cos tan atan acos asin)
I didn't try to get the extra digits, hence the different value from the rskey reported value.

Enter BaseN Hex mode. Get 2's complement of FFFF
Result: FFFF0001

Go to BaseN Dec mode.

Result: -65535

 

Low profile pocket machine typical of Casio of that era.

 

Single 3V CR2025 battery cell. 

 Undo the six steel screws to remove the back cover.

Back label:

Casio fx-3800P

DC 3VDC 0.0005W

Use Battery 3Vx1

Made in Japan

Casio Computer, Ltd.

 

The On-Off switch will get lose after removing the back cover and should be stored for later reassembly. 
Undo two extra screws to remove the PCA.
The LCD display assembly is attached to the PCB and it is not glued to the front panel. It is maintained in place by a foam that is pressed by the back cover.

One interesting note on the LCD assembly: The LCD itself is glued to a heavy metal frame. Not sure what was the engineering reasons behind this design choice. Most probably to give extra rigidity and protection, while giving the calculator more mass/weight for a more customer satisfying experience ?

 

  

No date codes on any component.

No identification in the SoC processor either.
The PCB reference is: G937-1 3

Only two passive components can be identified.

One SMD resistor marked as "224" (220000‎Ω = 220K‎Ω).

One legacy pass through tantalum polarized capacitor marked as "J335" (3300000pF = 3.3μF)