Note 2 - Summary of Significant Accounting Policies and Significant Judgments and Estimates - Stock Option Activity (Details) - $ / shares	12 Months Ended
	Sep. 29, 2018	Sep. 30, 2017	Oct. 01, 2016
Outstanding, unvested (in shares)	34,200	26,700
Outstanding, vested (in shares)	212,081	216,981
Outstanding (in shares)	246,281	243,681
Outstanding, weighted average exercise price (in dollars per share)	$ 8.36	$ 8.69
Outstanding, weighted average contractual life (Year)	3 years 277 days	3 years 346 days	4 years 208 days
Grants, unvested (in shares)	20,500	14,000
Grants, vested (in shares)
Share-based Compensation Arrangement by Share-based Payment Award, Options, Grants in Period, Gross	20,500	14,000
Grants, weighted average exercise price (in dollars per share)	$ 6.22	$ 2.50
Vested, unvested (in shares)	(10,000)	(5,900)
Vested, vested (in shares)	10,000	5,900
Vested, weighted average exercise price (in dollars per share)	$ 3.25	$ 3.61
Exercises (in shares)	(31,800)	0
Cancellations/forfeitures, unvested (in shares)		(600)
Cancellations/forfeitures, vested (in shares)	(7,844)	(10,800)
Cancellations/forfeitures (in shares)	(7,844)	(11,400)
Cancellations/forfeitures, weighted average exercise price (in dollars per share)	$ 9.68	$ 8.24
Outstanding, unvested (in shares)	44,700	34,200	26,700
Outstanding, vested (in shares)	182,437	212,081	216,981
Outstanding (in shares)	227,137	246,281	243,681
Outstanding, weighted average exercise price (in dollars per share)	$ 8.50	$ 8.36	$ 8.69
Exercises, vested (in shares)	(31,800)
Exercises, weighted average exercise price (in dollars per share)	$ 5.60