Looks like it should be as attached.

--Vassili

--- snip ---

'From Squeak3.3alpha of 30 January 2002 [latest update: #4730] on 2 
February 2002 at 6:13:26 pm'!

!VariableNode methodsFor: 'testing' stamp: 'vb 2/2/2002 18:11'!
index
	"This code attempts to reconstruct the index from its encoding in code."
	code < 0 ifTrue:[^nil].
	code > 256 ifTrue:[^code \\ 256].
	^code - (CodeBases at: self type)! !