I bought from a computer store during a localized power outage about 15 years ago (not the great blackout of 2003). I paid cash, the clerk hand-wrote a receipt

I bought from a computer store during a localized power outage about 15 years ago (not the great blackout of 2003). I paid cash, the clerk hand-wrote a receipt on a pre-printed form, and presumably they kept a second copy of the receipt to input electronically when the power eventually came back.