Olivetti Programma 101 Reference Manual page 13

14 The ROUTINE SELECTION KEYS V, W, Y and Z
direct the computer to the proper program or
subroutine.
15 The NUMERIC KEYBOARD uses the ten-key entry
system with provision for entry of a decimal point and a
negative sign. Keyboard entries are automatically
stored in the M register.
16 The CLEAR ENTRY KEY clears the entire keyboard
entry When keying in a program, a depression of the
clear key will erase the last instruction that has been
entered.
17 The START KEY restarts the computer in
programmed operation and is used to code a stop
instruction when keying in programs.
18 The REGISTER ADDRESS KEYS A, B, C, D, E, F
and R identify the corresponding registers. The
operating register M has no keyboard identification
since the computer automatically relates all instructions
to the M register unless instructed otherwise.
19 The SPLIT KEY combined with a register (e.g. C/)
divides that register into two equal parts. When storage
registers are split, the right portion of the split register
retains the original designation while the left side is
identified on the tape with the corresponding lower case
letter (e.g. C/ = c).
- 13 -