At 3 a.m. last Monday, an hour when sheriff's deputies like to say that "nothing moves" in Lououn County, much of the county's law enforcement brass -- Sheriff John R. Isom, Maj. Charles Cooper, Fire and Rescue Capt. William Goldfedder -- huddled around an emergency dispatcher's console at the Fire and Rescue Training Center on Sycolin Road.

Instead of the four dispatchers who would normally be on duty during the dead hours, nearly a dozen joined their bosses' vigil. They looked as if they ought to be orchestrating the capture of some notorious criminal, but they were waiting for a switch to be thrown -- transferring emergency communications from two antiquated systems at separate locations in Leesburg to the new $2 million facility in the center's basement.

That meant that the major players in the understated predawn drama ("Shouldn't there be a drum roll or something?" Cooper asked) were the Chesapeake & Potomac Telephone Co. technicians still testing 13 incoming 911 lines and several Motorola representatives on hand to coach dispatchers in the use of the equipment.

Six years in the planning and six months in the installation, the new center computerizes the communications system,, automatically sending the paging signals that sound sirens at fire and rescue stations and set off the beepers of their volunteers. That used to be done manually.

It also consolidates the dispatch operation. Until Monday, the fire and rescue dispatchers worked in the Jackson Professional Building on Gibson Street, the sheriff's dispatchers in a closet-like room without windows on the third floor of the jail. When either group needed to hand off a call or work together on one, they got on the telephone.

Now they can monitor the same call and see each other across the room. "The best part about it," said Gail Fletcher, supervisor of the fire and rescue dispatchers, "is that everyone will be here."

And after their previous accommodations, what a place: walls and carpet in muted blues, four wall-mounted televisions and windows with clear bulletproof glass instead of the nearly opaque glass that was originally proposed. "Hardly anything in this room was done without input from dispatchers . . . . They can see out, they can tell whether it's raining," Goldfedder said.

At the unveiling, all they could see outside was dark -- and inside, more company than they are ever likely to have again. The crowd at its height numbered well over two dozen, most of them clutching coffee cups after working through the weekend. And 90 minutes after the switch, they were still waiting to see if their new toys worked, the 911 lines as dormant as they usually are before sunup on a Monday.

"We chose this time to switch because we didn't want to lose any calls in the transition," said John Webb, emergency communications manager. "We're likely to sit around a while."

"I'll tell you one way we can find out if it works," Sheriff Isom said as the clock ticked on toward daylight. "Is there a pay phone around here?"

Isom had announced his intention to give up and go home when the call finally came at 4:31:27 a.m.

"Here it is," Webb said, bolting for the fire-and-rescue consoles on the west side of the room.

"Where is she, sir?" dispatcher Fletcher was saying to the 911 caller. "Is it on Pershing Avenue? On the right or the left? And it's a stone house? Is it facing Market Street? And you think it's Number 20 but you're not sure? Your name? Your number?"

Behind Fletcher, dispatcher John Colway reached into a file for a card bearing the name of the street and the nearest fire and rescue companies. From a list on the computer screen, he selected Medic 13 to respond to the call, told the computer to send the "pre-alert" -- a sustained beep alerting rescue personnel to a medical emergency (rather than the two short beeps indicating a fire) -- and then hit the paging command to set off alarm and beepers.

"Heart attack," he said into his headset, relaxing his grip on the "mouse" with which he had fed instructions to the computer. "Number 20 Pershing Avenue. Medic 13. O4:34."

"Good for you," Goldfedder said.

"Did you hit that pre-alert twice?" Fletcher teased.

"Just a little shaky," Webb consoled. "It's tough with 20 people watching."