Annual report [Section 13 and 15(d), not S-K Item 405]

Note 4 - Fair Value Measurements (Details Textual)

v3.25.3
Note 4 - Fair Value Measurements (Details Textual)
 12 Months Ended
Sep. 22, 2025
USD ($)
shares
Sep. 30, 2025
USD ($)
shares
Sep. 30, 2024
USD ($)
Oct. 03, 2024
yr
Sep. 03, 2024
USD ($)
Oct. 03, 2023
USD ($)
shares
Proceeds from Sale of Equity Securities, FV-NI   $ 393,217 $ 0      
Equity Securities, FV-NI, Unrealized Gain (Loss)   $ (323,773) (176,077)      
Fair Value, Inputs, Level 3 [Member] | BWV Preferred Stock [Member] | Measurement Input, Price Volatility [Member]            
Equity Securities, FV-NI, Measurement Input       0.79    
Fair Value, Inputs, Level 3 [Member] | BWV Preferred Stock [Member] | Measurement Input, Expected Term [Member]            
Equity Securities, FV-NI, Measurement Input | yr       3    
Fair Value, Inputs, Level 3 [Member] | BWV Preferred Stock [Member] | Measurement Input, Discount Rate [Member]            
Equity Securities, FV-NI, Measurement Input       0.35    
Fair Value, Inputs, Level 3 [Member] | BWV Preferred Stock [Member] | Measurement Input, Discount for Lack of Marketability [Member]            
Equity Securities, FV-NI, Measurement Input       0.15    
Fair Value, Inputs, Level 3 [Member] | BWV Preferred Stock [Member] | Measurement Input, Probability Of Dissolution [Member[            
Equity Securities, FV-NI, Measurement Input       0.60    
Series D Preferred Stock [Member] | ONCO [Member]            
Investment Owned, Balance, Shares (in shares) | shares 16,099          
ONCO Warrant [Member]            
Investment Owned, Balance, Shares (in shares) | shares 846,975 846,975        
Fair Value, Measurement with Unobservable Inputs Reconciliation, Recurring Basis, Asset Value   $ 760,987 0      
ONCO Warrant [Member] | ONCO [Member]            
Investment Owned, Balance, Shares (in shares) | shares 4,362,827          
ONCO Series D Preferred Stock and ONCO Warrant [Member] | ONCO [Member]            
Proceeds from Sale of Equity Securities, FV-NI $ 12,900,000          
Common Stock [Member]            
Proceeds from Sale of Equity Securities, FV-NI   400,000        
Investment Owned, Balance, Principal Amount         $ 700,000  
Equity Securities, FV-NI, Unrealized Gain (Loss)   $ (300,000) $ (200,000)      
Series A Convertible Preferred Stock [Member]            
Investment Owned, Balance, Shares (in shares) | shares           3,000
Fair Value, Measurement with Unobservable Inputs Reconciliation, Recurring Basis, Asset Value           $ 900,000