Rockwall, Texas ? Sherry Neal walked over to the refrigerated shelves of her 7-Eleven store, consulted a small hand-held computer and instantly got everything she wanted to know about her store’s supply of turkey sandwiches.

With a couple taps on the wireless device, the store manager placed an order for the next day’s sandwiches without ever leaving the aisle.

Neal is helping test a wireless NEC Corp. computer that 7-Eleven — the nation’s largest convenience-store chain — has put in the hands of supervisors in 10 Dallas-area stores with an eye toward outfitting all its 5,300 U.S. locations next year.

Officials say the devices will reduce excess inventory and dramatically boost sales by eliminating one of retailing’s oldest curses: running out of hot-selling items.

Retailers in general and convenience stores in particular have been slow to adopt new technology, analysts say.

Now, prompted by the example of Wal-Mart Stores Inc. and helped by the falling price of technology, they are playing catch-up.

“Retailers are trying to get back to where they were in 1905,” said Cathy Hotka, a retail consultant in Arlington, Va. “Back then they knew you, knew your credit, knew what you wanted to buy and how to stock it.”

The NEC device is loaded with software that helps managers predict demand for perishable food — from hot dogs to whipping cream — by taking factors such as the weather forecast into account. Hot weather helps Slurpee sales. Rain is a killer.

Striking the right balance between supply and demand is critical in the thin-margin world of food stores. A widely quoted 2002 study by Emory University estimated that stores lose 4 percent of potential sales because they run out of items customers want.

7-Eleven store manager Sherry Neal uses a hand-held wireless computer to keep stock of perishable items. She was testing the device Wednesday at her store in Rockwall, Texas.

Neal, the 7-Eleven store manager in Rockwall, Texas, used the machine to get an instant recommendation of how many bags of potato chips to order for delivery overnight. She could go along with the computer’s suggestion or override it.

“It brings the computer out here on the floor,” Neal said.