INCOME TAXES (Deferred tax assets and liabilities for federal and state income taxes) (Details) - USD ($) $ in Thousands	Jun. 30, 2021	Jun. 30, 2020
Deferred tax assets:
Federal and State NOL carryforward	$ 20	$ 21
Research and other credits	65	65
Reserves and accruals	461	438
Stock based compensation	268	110
Unrealized losses	61	455
Inventory	371	334
Total gross deferred tax assets	1,246	1,423
Less: valuation allowance	(158)	(543)
Total deferred tax assets	1,088	880
Deferred tax liabilities:
Property and equipment, principally due to differing depreciation methods	(523)	(577)
Deferred state tax	(38)	(33)
Other	(64)	(11)
Total gross deferred tax liabilities	(625)	(621)
Net deferred tax assets	$ 463	$ 259