Note 4 - Revenue - Disaggregation By Revenue (Details) - USD ($)	3 Months Ended	6 Months Ended
Mar. 27, 2021	Mar. 28, 2020	Mar. 27, 2021	Mar. 28, 2020
Net revenue	$ 616,554	$ 722,751	$ 783,479	$ 1,388,676
Engineering Services [Member]
Net revenue	242,754	457,818	242,754	866,642
Equipment Sales [Member]
Net revenue	$ 373,800	$ 264,933	$ 540,725	$ 522,034

Amount, including tax collected from customer, of revenue from satisfaction of performance obligation by transferring promised good or service to customer. Tax collected from customer is tax assessed by governmental authority that is both imposed on and concurrent with specific revenue-producing transaction, including, but not limited to, sales, use, value-added and excise.

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+ Details