CESIL

Cesil, or Computer Education in Schools Instruction Language, was a programming language designed to introduce pupils in British schools to Assembly language. It is a low level language containing a total of fourteen instructions:

• Load value - place the immediate value or the contents of the variable named in the accumulator.
• Store variable - place the contents of the accumulator in the variable.
• Jump label - transfer control to location labelled.
• Jineg label - transfer control to location labelled if the accumulator contains a negative value.
• Jizero label - transfer control to location labelled if the accumulator contains zero.
• Print literal - output the following string, delimited by single quotes.
• Line - output a carriage return
• In - allow user to input a numerical value from the console.
• Out - Output the contents of the accumulator as a decimal integer, signed if negative.
• Add value - add the variable or immediate integer value to the accumulator.
• Subtract value - subtract the variable or immediate integer from the accumulator.
• Multiply value - place the product of the accumulator and the variable or immediate integer in the accumulator.
• Divide value - place the contents of the accumulator divided by the value in the accumulator.
• Halt - return control to console.

Examples

The following totals the integers in runtime data section until it encounters a negative value and prints the total.

        LOAD    0
LOOP    STORE   TOTAL
        IN
        JINEG   DONE
        ADD     TOTAL
        JUMP    LOOP

DONE    PRINT   "The total is: "
        LOAD    TOTAL
        OUT
        LINE
        HALT

        %
        1
        2
        3
        -1

[Output of above program running...] 
        The total is:  6

External links

• http://www.obelisk.me.uk/cesil/