(8) Income Taxes - Deferred tax assets (Details) - USD ($)	Dec. 31, 2016	Dec. 26, 2015
Deferred Tax Assets:
Net operating loss carryforwards	$ 363,000
Stock compensation	628,000	553,000
Credit carryforwards	1,265,000	1,018,000
Inventory	369,000	424,000
Accrued liabilities	27,000	39,000
Depreciation	171,000	112,000
Other	4,000	5,000
Gross deferred tax assets	2,827,000	2,151,000
Valuation allowance
Net deferred tax assets	$ 2,827,000	$ 2,151,000