Although the P6040 was very like a calculator, it was a real computer featuring 16 KB ROM, 2 KB RAM and a tiny BASIC programming language.
A three position selector allowed to enter a BASIC program (LOAD position), execute (EXECUTE) or debug by running one instruction at a time (STEP). Sadly, out of the 2 KB of available RAM, only one was available for BASIC program and variables. Hopefully, an optional 2 KB RAM extension was available.
Programs could be listed or executed using the red diode display or the built-in alphanumeric printer. They was saved on Olivetti specific 2.5" 3 KB mylar minidiscs through the built in disc drive.
Three versions of the P-6040 were sold. The first allowed programs to be created, edited and executed; the second only allowed programs to be read from the minidisc and executed; the third, stangely, allowed programs to be created and saved but not executed.
Thanks to Steven Williams for the donation of his P6040!
Thanks to Gérard Touitou for information and pictures