\title{Servo Stacks}

Servos have 16 stacks of memory, one for each color.
A stack is a list of values.
Only the top value is immediately accessible,
and other values can be put above it.

Each stack can hold 16 items.
They can hold text,
numbers,
booleans ('True' or 'False'),
\link{colorscanner}{colors},
and servo instructions.



Some of the stacks have particular uses:

WHITE: This stack is used as a staging area for moving items between other stacks.

BLACK: Any error messages are written to this stack.

YELLOW: This is the parameter stack. When an instruction does something to "the stack", it means this one.

RED: The contents of this stack get executed whenever the servo entres a block.
