Note 9 - Shareholders' Equity, Redeemable Convertible Preferred Stock, Options and Warrants - Option Activity (Details) - USD ($)		12 Months Ended
	Mar. 03, 2023	Dec. 31, 2023	Dec. 31, 2022	Dec. 31, 2021
Outstanding (in shares)		24,993,500	20,777,500
Outstanding, weighted average exercise price (in dollars per share)		$ 0.07	$ 0.06
Outstanding, aggregate intrinsic value		$ 17,000	$ 0	$ 627,615
Granted (in shares)		3,100,000	8,150,000
Granted, weighted average exercise price (in dollars per share)		$ 0.04	$ 0.09
Exercised (in shares)		0	(1,200,000)
Exercised, weighted average exercise price (in dollars per share)			$ 0.04
Exercised, aggregate intrinsic value			$ 57,000
Forfeited (in shares)	(1,000,000)	(3,306,000)	(1,734,000)
Forfeited, weighted average exercise price (in dollars per share)		$ 0.08	$ 0.08
Outstanding (in shares)		24,787,500	24,993,500
Outstanding, weighted average exercise price (in dollars per share)		$ 0.05	$ 0.07
Outstanding, weighted average remaining contractual life (Year)		5 years 4 months 24 days
Exercisable (in shares)		19,372,500
Exercisable, weighted average exercise price (in dollars per share)		$ 0.05
Exercisable, weighted average remaining contractual life (Year)		4 years 7 months 6 days
Exercisable, aggregate intrinsic value		$ 16,000