Note 12 - Equity Transaction and Stock-based Compensation - Share-based Compensation, Shares Authorized under Stock Option Plans, by Exercise Price Range (Details) - $ / shares	12 Months Ended
	Jun. 30, 2018	Jun. 30, 2017	Jun. 30, 2016
Range of Exercise Price, Lower Limit (in dollars per share)	$ 0.09
Range of Exercise Price, Upper Limit (in dollars per share)	$ 0.25
Outstanding (in shares)	2,439,250	2,718,183	2,870,950
Weighted Average Exercise Price, Outstanding (in dollars per share)	$ 0.11	$ 0.29	$ 0.40
Weighted Average Remaining Contractual Life (Year)	5 years 219 days
Exercisable (in shares)	2,439,250	2,506,683
Weighted Average Exercise Price, Exercisable (in dollars per share)	$ 0.11	$ 0.30
Range One [Member]
Range of Exercise Price, Lower Limit (in dollars per share)	0.09
Range of Exercise Price, Upper Limit (in dollars per share)	$ 0.10
Outstanding (in shares)	1,846,000
Weighted Average Exercise Price, Outstanding (in dollars per share)	$ 0.09
Weighted Average Remaining Contractual Life (Year)	6 years 292 days
Exercisable (in shares)	1,846,000
Weighted Average Exercise Price, Exercisable (in dollars per share)	$ 0.09
Range Two [Member]
Range of Exercise Price, Lower Limit (in dollars per share)	0.14
Range of Exercise Price, Upper Limit (in dollars per share)	$ 0.15
Outstanding (in shares)	443,250
Weighted Average Exercise Price, Outstanding (in dollars per share)	$ 0.14
Weighted Average Remaining Contractual Life (Year)	182 days
Exercisable (in shares)	443,250
Weighted Average Exercise Price, Exercisable (in dollars per share)	$ 0.14
Range Three [Member]
Range of Exercise Price, Lower Limit (in dollars per share)	0.23
Range of Exercise Price, Upper Limit (in dollars per share)	$ 0.25
Outstanding (in shares)	150,000
Weighted Average Exercise Price, Outstanding (in dollars per share)	$ 0.24
Weighted Average Remaining Contractual Life (Year)	8 years 146 days
Exercisable (in shares)	150,000
Weighted Average Exercise Price, Exercisable (in dollars per share)	$ 0.24