CTLR RECEIVED MSAW WARNING AFTER DSNDING SMA TO MIN IFR ALT. SITUATION: NO VIDEO MAP OVERLAY SHOWING MIN IFR ALT IN ARTCC RADAR SECTORS.

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RUSSELLVILLE; AR; IS A MOUNTAINOUS AREA INVOLVING A NUMBER OF DIFFERENT MIA'S IN A RELATIVELY SMALL AREA. THESE MIA'S ARE DEPICTED FOR CTLRS ON CHARTS LOCATED AT EACH SECTOR. UNFORTUNATELY; THOSE CHARTS CONTAIN A MIN OF INFO MAKING IT DIFFICULT (AT BEST) FOR THE CTLR TO ACCURATELY DETERMINE THE BOUNDARIES FOR THE VARIOUS MIA'S. AS A RESULT; THE CTLR IS OFTEN FORCED TO GIVE A HIGHER ALT (SOMETIMES AS MUCH AS 600 FT); SINCE THE EXACT POS OF THE MIA CHANGE CANNOT BE DETERMINED. THIS PROVIDES A DISSERVICE TO THE PUBLIC; AND COULD CAUSE AN ACCIDENT IN THE EVENT THE WRONG MIA WERE GIVEN. AT MEMPHIS CENTER; A TEST WAS RUN IN WHICH A VIDEO DISPLAY OF THE CHART WAS PROVIDED ON THE SCOPE. UNFORTUNATELY; THE SECTOR CHOSEN FOR THE TEST HAD VERY FEW MIA'S; EACH HAVING MINOR ALT DIFFERENCES FROM THE OTHER. AS A RESULT; IT WAS CONCLUDED THAT THE VIDEO MAP WAS UNNECESSARY. ON THE CONTRARY; PROVIDING MAX SAFETY TO THE PUBLIC BY USING A FILTER KEY SELECT VIDEO MAP OF MIA'S IS A NECESSITY. IN THIS CASE; AN ACFT WAS GIVEN 3700 FT TO MAINTAIN UNTIL IAF INSTEAD OF 3400 FT DUE TO MSAW RESOLUTION. THIS CAUSED THE ACFT TO EXECUTE A PROC TURN BEFORE BREAKING OUT FOR A VISUAL. THE SAME THING OCCURRED WITH ANOTHER SMA WHERE ACCORDING TO THE MIA CHART; 3400 FT SHOULD HAVE BEEN GOOD. INSTEAD; A MSAW ALERT WAS ACTIVATED BY SMA BEFORE ANY ALT WAS VIOLATED. EITHER THE CHART WAS WRONG OR THE PROGRAMMED MSAW DISTANCE WAS WRONG. IN THIS CASE IT WAS NOT A PROBLEM; HOWEVER; AROUND HARRISON; AR; WHERE ACFT ARE NONRADAR; CTLRS CAN ONLY GUESS AS TO MIA BOUNDARIES WITHOUT THE BENEFIT OF MSAW. THE POTENTIAL FOR AN ACCIDENT THERE; AS OTHER PLACES; IS GREAT.