Since version 0.9

Syntax:

const <varname> = <number>

The CONST directive defines a constant. The constant can be subsequently used as a regular variable, except that it is read-only.

Constants of any numeric types (bytes, integers or floats) may be defined. The number must be a numeric literal (no expression is allowed here).

Example:

const BORDER = $d020
const WHITE! = 1

poke BORDER, WHITE!

const PI% = 3.1415926