Inventories (Details) (USD $) In Thousands, unless otherwise specified	Oct. 31, 2012	Jul. 31, 2012
Inventories
Raw materials and purchased components	$ 1,189	$ 1,151
Finished goods	6,076	6,249
Total	7,265	7,400
Obsolescence reserve	(2,142)	(2,139)
Inventories	$ 5,123	$ 5,261