The keyboard is really good. 
Attention: The backspace is called ‘roubout’ and you can use it with SHIFT! on the right side on top (same place like backspace)
There are three modes:
  • Default Inser-Line (L)
  • Commands (K) - Commands : Shift-Function > The command
  • Graphics (G) - Create the char with graphics (First Shift Graphics > Shift Key)
The whole system is a token coding thing. 

 
In the manual first there is the explanation, how to use it as calculator.

PRINT 2 3
(If you are as default in the command-mode (K), you just have to click P and it creates a print)

You can also write LET a=10 and than work with then in the shell.
 
You can enter all commands from the beginning. you press P and it makes PRINT out of it. and than it knows that a value comes etc.It is a very structured computer.
 
enter 
10 and code [new function]

# edit:
a. move in the source code 
b. on the right line SHIFT EDIT
c. edit down > [ENTER]

# run
run
 
 
 
The system is very clever and really works. You are faster than you think and the system helps a lot!
 
 
sold to amstrad > sinclair invented other computers
 

Installation

really find the correct channel in tv! 
coding:assembler
 
technology:processor
made with zx 80 a processor after 4004/8008/8080