CASIO fx-4000P scientific calculator from 1986

[jebem]

This small pocket calculator was manufactured in Japan after 1986 week 43 according to the most recent chip date found in the PCA of this specimen.

The year is 1985.
Casio released this model with an impressive set of features for its time:
- Re-configurable RAM memory partitioning. Default values are 26 x 8-byte registers and 550 programming steps.
- Fully merged programming model.
- Conditional and unconditional jumps, subroutines.
- Support for indirect register addressing.
- User friendly programming environment. Keystrokes displayed by its function names. Easy editing and debugging.
- Alphanumeric capability.




Calculator forensics: arcsin(arccos(arctan(tan(cos(sin(9)))))) = 8.999686999
Remaining digits: 9 - Ans Exe x 10000000 = 31.3001




5x7 dot matrix LCD display, natural language algebraic input.



Friendly program editor.
Keystrokes displayed by its function names.
Left and right cursors allows easy editing.
Program memory usage updated in real time at the top right.




Dot matrix LCD display with full contrast ON to show all elements.




Accessing the battery compartment.
It uses two CR2032 in series for a total of 6Volt at 1.7mA average current consumption.



(to be continued)