In childhood I used to program on MK-61 soviet calculator. It had 4 operating registers (X, Y, Z, T) and 15 storage registers. Program could have 105 steps.
As I recall it had commands like:
- swap X and Y registers
- shift registers (Z to T, Y to Z, X to Y)
- copy from storage register (1..15) to X
- copy from X to storage register (1..15)
- if X < 0 then go to program step ##
- perform operation (+, -, *, /) using X and Y values and put result to X
Q: Is this command set an assembly language? Did I have a basic idea of assembly languages using this device?
UPDATE Turns out it is something called "keystroke programming"
Funny fact: similar calculator (like this but with energy independent memory) was used as a back-up hardware for space mission trajectory calculations in 1988. :-)