I loved this machine. Stuyvesant HS in NYC had one in the late 60’s, and you had to be strategic to get use it. (In the same room was an IBM 1130. Stuyvesant had two programming classes in 1967-68, Fortran IV, and more advanced Fortran IV.)

Later, in 1969, I used the HP9100A desktop calculator. This was a 30kg HP35 with 196 steps of memory, a CRT which showed either 3 steps of the program, or the three rpn registers. It was the successor to the Programma, and was replaced by a series of desk calculators with more memory, LED displays, the ability to control analog plotters, and ultimately BASIC programming.

But the value of the early calculators like the Programma was in teaching efficient algorithm design with limited memory. While this was completely obviated in scientific programming by the late 70’s, I’m sure it served as a first introduction to software engineers writing in assembly language.

I think the most interesting feature of old desktop calculators was the use of the 'magnetostrictive metal wire acoustic delay line' for memory.

We had one of these in my school in the seventies. I remember using it although I can't recall the technical details now other than it being extremely limited.

My dad was a civil engineer who loved computing so had the luck to be exposed to all his purchases. Memorable for me this Programma 101, an HP-67 (could be programmed with magnetic strips! And had Polish notation :), a couple of Olivetti M24 with GWBasic as OS...

What were typical applications of these computers? And who programmed it?