CONDENSED CONSOLIDATED BALANCE SHEETS - USD ($)	Jun. 30, 2021	Dec. 31, 2020
Current assets
Cash	$ 13,194,000	$ 8,764,000
Investment securities, available-for-sale, at fair value	1,243,000	1,228,000
Accounts receivable, net
Trade - billed (less allowance for doubtful accounts of approximately $400), including contract retentions	11,826,000	9,798,000
Trade - unbilled	636,000	742,000
Inventories, net
Raw materials	1,295,000	643,000
Finished goods	1,448,000	1,551,000
Prepaid expenses and other assets	558,000	615,000
Total current assets	30,200,000	23,341,000
Property and equipment, net	18,612,000	18,602,000
Deferred buy-back lease asset, net	3,818,000	4,237,000
Other assets	287,000	319,000
Total assets	52,917,000	46,499,000
Current liabilities
Accounts payable - trade	2,944,000	1,866,000
Accrued expenses and other liabilities	577,000	875,000
Deferred revenue	2,617,000	1,774,000
Accrued compensation	1,496,000	1,318,000
Accrued income taxes	1,045,000	470,000
Deferred buy-back lease obligation	1,195,000	1,203,000
Operating lease liabilities	87,000	85,000
Current portion of PPP loan	2,692,000	0
Current maturities of notes payable	556,000	740,000
Customer deposits	833,000	569,000
Total current liabilities	14,042,000	8,900,000
Deferred revenue	1,423,000	600,000
Deferred buy-back lease obligation	3,196,000	3,790,000
Operating lease liabilities	167,000	211,000
Notes payable - less current maturities	3,959,000	4,196,000
PPP loan - less current portion	0	2,692,000
Deferred tax liability	2,457,000	2,461,000
Total liabilities	25,244,000	22,850,000
Stockholders' equity
Preferred stock, $.01 par value; authorized 1,000,000 shares, none issued and outstanding	0	0
Common stock, $.01 par value; authorized 8,000,000 shares; 5,326,595 and 5,279,411 issued and 5,202,158 and 5,202,158 outstanding, respectively	53,000	52,000
Additional paid-in capital	6,576,000	6,405,000
Treasury stock, at cost, 40,920 shares	(102,000)	(102,000)
Retained earnings	21,146,000	17,294,000
Total stockholders' equity	27,673,000	23,649,000
Total liabilities and stockholders' equity	$ 52,917,000	$ 46,499,000