Condensed Consolidated Statements of Cash Flows (Unaudited) - USD ($)	9 Months Ended
	Mar. 31, 2020		Mar. 31, 2019	[1]
Operating activities:
Net (loss) income	$ (623,835)		$ 282,599	[2],[3]
Adjustments to reconcile net (loss) income to net cash provided by operating activities:
(Recovery of) provision for doubtful accounts	(8,938)		4,039
Depreciation of equipment and leasehold improvements	258,401		336,946
Stock-based compensation expense	428,228		383,425
Deferred income taxes	13,276		(13,277)
Change in cash surrender value of life insurance	(156,398)		(34,801)
Change in deferred compensation accrual	37,016		131,965
Deferred compensation paid	(112,500)		(112,500)
Net changes in operating assets and liabilities:
Accounts receivable	110,705		1,893,559
Inventories	1,859,887		(590,987)
Prepaid expenses and other current assets	(254,612)		(68,539)
Income taxes receivable	35,426		(9,776)
Accounts payable	(1,027,292)		(222,292)
Accrued liabilities	(15,616)		(47,835)
Deferred revenue	(203,960)		(96,118)
Net cash provided by operating activities	339,788		1,836,408
Investing activities:
Purchase of equipment and leasehold improvements	(391,151)		(118,647)
Life insurance premiums paid	(112,956)		(123,076)
Net cash (used in) investing activities	(504,107)		(241,723)
Financing activities:
Proceeds from exercise of stock options			46,677
Net cash provided by financing activities			46,677
Net (decrease) increase in cash and cash equivalents	(164,319)		1,641,362
Cash and cash equivalents at beginning of period	2,228,282	[4]	1,081,533
Cash and cash equivalents at end of period	$ 2,063,963		$ 2,722,895

[1] As adjusted for change in accounting principle (Note 2)

[2] As adjusted for change in accounting principle (Note 2)

[3] As adjusted for change in accounting principle (Note 2)

[4] As adjusted for change in accounting principle (Note 2)