CONDENSED CONSOLIDATED STATEMENTS OF CASH FLOWS (UNAUDITED) - USD ($) $ in Thousands	9 Months Ended
	Sep. 27, 2019	Sep. 28, 2018
Cash flows from operating activities:
Net income (loss)	$ (1,242)	$ 2,689
Adjustments to reconcile net income (loss) to net cash provided by (used in) operating activities:
Depreciation and amortization	198	200
Bad debt expense	457	0
Provision for excess and obsolete inventory	0	219
Noncash lease expense	337	396
Other	30	136
Changes in operating assets (increases in parenthesis) and liabilities (decreases in parenthesis):
Accounts receivable	(484)	(2,450)
Lease receivable	195	184
Inventories	457	315
Operating lease right-of-use asset	(44)	0
Contract revenue in excess of billings	(79)	(558)
Prepaid expenses and other assets	434	(116)
Accounts payable	(478)	418
Accrued liabilities	369	648
Accrued pension and retirement liabilities	(124)	(179)
Billings in excess of contract revenue	(1,761)	850
Operating lease liability	(318)	(393)
Net cash provided by (used in) operating activities	(2,053)	2,359
Cash flows from investing activities:
Purchases of property and equipment	(100)	(80)
Proceeds from sale of property and equipment	0	28
Net cash used in investing activities	(100)	(52)
Cash flows from financing activities:
Proceeds for shares issued on exercise of options	21	0
Principal payments on long-term debt	(177)	(167)
Net cash used in financing activities	(156)	(167)
Net increase (decrease) in cash, cash equivalents, and restricted cash	(2,309)	2,140
Cash, cash equivalents, and restricted cash as of beginning of the period	8,585	5,588
Cash, cash equivalents, and restricted cash as of end of the period	6,276	7,728
Supplemental disclosures of non-cash investing and financing activities
New operating lease	2,698	0
Supplemental disclosures of cash flow information
Cash paid during the period for: Interest	65	74
Cash paid during the period for: Income taxes	$ 46	$ 103