SMT Y CLB TO OCCUPIED ALT. HAD LTSS FROM SMT Y. SYS ERROR.

Narrative

SMA X PROGRESSED LBY A COMPUTER HDOF WAS INITIATED TO ZME AND WAS ACCEPTED. SMA X POS WAS APPROX 3 MI NE OF LBY. THIS AREA N OF LBY OFTEN REQUIRES NON-RADAR SEPARATION DUE TO LIMITED RADAR COVERAGE BELOW 4000 FT. THE HDOF WAS MADE EARLY TO AVOID SMA X BECOMING A NON-RADAR SIT REQUIRING VERBAL COORD WITH ZME. AT THE TIME I MADE THE HDOF; I BELIEVED SMA X TO BE SEVERAL MI FURTHER NE OF LBY. I THOUGHT THAT SMA X WOULD NEARLY BE OUT OF ZHU AIRSPACE BY THE TIME THE DATA BLOCK TIMED OUT. EVEN IF IT DID TIME OUT BEFORE LEAVING MY AIRSPACE; I BELIEVE I WOULD SEE A TARGET OR A LIMITED DATA BLOCK APPEAR INTERMITTENTLY OR I'D REMEMBER ITS LAST KNOWN POS. SMA X DID TIME OUT EARLIER THAN I EXPECTED. THE ALL LIMITED DATA BLOCKS KEY SHOULD HAVE BEEN SELECTED. THE RADAR TARGET WAS NOT OBSERVED BY MYSELF AFTER SMA X BECAME NON- RADAR APPROX 12 MI NE OF LBY. THE COMPUTER PRINTOUT OF SMA X INDICATED OCCASIONAL RADAR RETURNS. WHEN SMT Y DEPARTED VFR; REQUESTING IFR CLRNC; SMA X HAD TIMED OUT ABOUT 1 MIN 31 SECONDS PREVIOUSLY. THERE WAS NO VISIBLE TARGET OR LIMITED DATA BLOCK IN THE AREA. SMT Y WAS ISSUED AN IFR CLRNC. ZME'S PATCH WENT OFF WHEN THE ACFT WERE APPROX 4 1/2 MI HORIZ AND 200 FT VERT. A ZME SUPVR CONTACTED A ZHU SUPVR; THAT ZHU SUPVR NOTIFIED ME OF THE ERROR. NON-RADAR PROCS SHOULD HAVE BEEN FOLLOWED; INCLUDING RETAINING THE FLT PROGRESS STRIP ON THE BOARD UNTIL SMA X IS KNOWN TO BE CLR OF ZHU AIRSPACE. I SHOULD HAVE ASKED ZME TO ADVISE ME WHEN SMA X WAS CLR OF MY AIRSPACE.