> Some large stores probably would have the systems to handle it...
What systems to handle it?
The cashier puts the check under the cash tray like you do for $100 bills, and then you toss the check in the cash bag that you send to the bank that night or at the end of the week or whatever, and the bank handles the check.
Electronic check readers to take advantage of the Check 21 rules. I'm not sure how many places still have them but they were a fixture of large store checkouts 20-ish years ago when the rules came out. IIRC Walmart (and probably other stores but I have vague memories of Walmart...) even had a printer they could put a standard check into that printed the front information (date, dollar amount in words and digits, memo) for you.
What systems to handle it?
The cashier puts the check under the cash tray like you do for $100 bills, and then you toss the check in the cash bag that you send to the bank that night or at the end of the week or whatever, and the bank handles the check.