Statements Of Cash Flows - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2022	Dec. 31, 2021
Cash flows from (used in) operating activities
Net income	$ 100	$ 410
Adjustments to reconcile net income to net cash from (used in) operating activities:
Depreciation and amortization	145	295
Deferred income taxes	(48)	38
Stock-based compensation expense	3	5
Interest accrued on Treasury Bills	(8)	(2)
Other	0	(7)
Change in:
Trade receivables	(156)	(48)
Inventories	(82)	(91)
Other current assets	(26)	(18)
Accounts payable	(75)	152
Accrued expenses	8	12
Income taxes receivable	(8)	23
Net cash from (used in) operating activities	(147)	769
Cash flows from investing activities
Purchases of Treasury Bills	(6,971)	(11,999)
Proceeds from the maturity of Treasury Bills	8,000	17,000
Purchase of property and equipment	(65)	(141)
Net cash from investing activities	964	4,860
Cash flows from (used in) financing activities
Payments on financing lease	(6)	(6)
Proceeds from the exercise of common stock options	122	0
Net cash from (used in) financing activities	116	(6)
Net increase in cash and cash equivalents	933	5,623
Cash and cash equivalents, beginning	6,713	1,090
Cash and cash equivalents, ending	7,646	6,713
Supplemental cash flow information
Cash paid during the year for income taxes	28	15
Cash paid during the year for interest	$ 1	$ 1