INCOME TAXES (Deferred tax assets and liabilities for federal and state income taxes) (Details) - USD ($) $ in Thousands	Jun. 30, 2020	Jun. 30, 2019
Deferred tax assets:
Federal & State NOL carryforward	$ 21	$ 23
Research & other credits	65	347
Reserves and accruals	438	431
Stock based compensation	110	9
Unrealized losses	455
Inventory	334	357
Other intangibles		37
Other		147
Total gross deferred tax assets	1,423	1,351
Less: valuation allowance	(543)	(477)
Total deferred tax assets	880	874
Deferred tax liabilities:
Property and equipment, principally due to differing depreciation methods	(577)	(527)
Deferred state tax	(33)	(81)
Other	(11)	(6)
Total gross deferred tax liabilities	(621)	(614)
Net deferred tax assets	$ 259	$ 260