Condensed Consolidated Statements of Operations (Unaudited) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2023	Jun. 30, 2022	Jun. 30, 2023	Jun. 30, 2022
REVENUES	$ 403	$ 370	$ 844	$ 787
Costs and expenses:
Manufacturing cost of sales	208	227	400	469
Engineering, selling and administrative	633	623	1,191	1,645
OPERATING LOSS	(438)	(480)	(747)	(1,327)
Other income (expense):
Interest income, net	275	9	473	5
Investment income (loss)	43	(2,373)	388	(2,328)
Other (expense) income, net	(12)	1	(24)	2
Total other income (expense), net	306	(2,363)	837	(2,321)
INCOME (LOSS) FROM CONTINUING OPERATIONS BEFORE INCOME TAXES	(132)	(2,843)	90	(3,648)
Income tax (benefit) expense	(2)	(588)	63	(754)
NET INCOME (LOSS) FROM CONTINUING OPERATIONS	(130)	(2,255)	27	(2,894)
Income from discontinued operations, net of tax	0	457	0	1,265
NET (LOSS) INCOME	$ (130)	$ (1,798)	$ 27	$ (1,629)
Net (Loss) Income per Basic Share:
Continuing operations (in dollars per share)	$ (0.02)	$ (0.42)	$ 0.01	$ (0.54)
Discontinued operations (in dollars per share)	0	0.08	0	0.23
Total Net (Loss) Income per Basic Share (in dollars per share)	(0.02)	(0.34)	0.01	(0.31)
Net (Loss) Income per Diluted Share:
Continuing operations (in dollars per share)	(0.02)	(0.42)	0.01	(0.54)
Discontinued operations (in dollars per share)	0	0.08	0	0.23
Total Net (Loss) Income per Diluted Share (in dollars per share)	$ (0.02)	$ (0.34)	$ 0.01	$ (0.31)
Weighted average shares outstanding:
Basic (in shares)	5,352,937	5,334,187	5,352,937	5,329,080
Dilutive (in shares)	5,352,937	5,334,187	5,352,937	5,329,080