Note 6 - Income Taxes - Deferred Income Tax Assets (Details) - USD ($) $ in Thousands	Dec. 31, 2016	Dec. 31, 2015
Deferred tax assets:
Net operating loss carry forwards	$ 12,295	$ 11,461
Engineering credit carry forwards	1,830	1,771
Inventory reserves	1,015	1,412
Capital loss and other credit carry forwards	21	67
Allowance for bad debts and returns	45	44
Capitalized inventory costs, stock compensation and other accruals	596	784
Total gross deferred tax assets	15,802	15,539
Less valuation allowance on deferred tax assets	(15,765)	(15,448)
Net deferred tax assets	37	91
Deferred tax liabilities:
Depreciation and other	(37)	(91)
Total deferred tax liabilities	(37)	(91)
Net deferred taxes