EVEN - Align program counter on even byte boundry:
EVEN
When the assembler encounters this directive the current internal program
counter used for code generation will be aligned to an even byte boundry. For
generated binaries that do not support the logical division of code sections
that do not have any data or code in between sections zero value bytes will be
generated.
Example:
org $1000 * Set the program counter to $1000
nop * Program counter is $1001 after opcode
even * Advance the program counter to $1002