Note 7 - Stockholders' Equity - Warrant Activity (Details) - $ / shares	6 Months Ended	12 Months Ended
	Mar. 31, 2024	Sep. 30, 2023
Outstanding as of September 30, 2023 (in shares)	2,148,000
Outstanding as of September 30, 2023 (in dollars per share)	$ 1.33
Outstanding as of September 30, 2023 (Year)	7 months 17 days	1 year 1 month 17 days
Outstanding as of December 31, 2023 (in shares)	2,148,000	2,148,000
Outstanding as of December 31, 2023 (in dollars per share)	$ 1.33	$ 1.33
Exercisable at December 31, 2023 (in shares)	2,148,000
Exercisable at December 31, 2023 (in dollars per share)	$ 1.33
Exercisable at December 31, 2023 (Year)	7 months 17 days