Note 2 - Summary of Significant Accounting Policies - Allowance for Doubtful Accounts (Details) - USD ($)	12 Months Ended
	Sep. 30, 2020	Sep. 30, 2019
Allowance for doubtful accounts	$ 200,000	$ 200,000
Additions Charged to Costs and Expenses	116,000	8,000
Accounts Charged off less Recoveries	(66,000)	(8,000)
Allowance for doubtful accounts	$ 250,000	$ 200,000