diff --git a/resources/BSM_Class/BSM.m b/resources/BSM_Class/BSM.m
index af3d638..6f5cca0 100644
--- a/resources/BSM_Class/BSM.m
+++ b/resources/BSM_Class/BSM.m
@@ -12,14 +12,14 @@ classdef BSM<handle
         ActiveColumns %store the columns to be analized
         U_orig %store the U field of SPM
         TargetFolder %target folder
-        % option below obsolete? 
+        % option below obsolete?
         BSMToolboxPath%store path to BSMToolbox
         SPMPath;%store path to SPM folder
         SPMIndexList=[];
     end
     properties (Dependent) %dependent properties
         NumSPMs% number of SPM.mat files to process
-
+        
     end
     properties %constants
         BSMMethod={'Traditional BSM Rissman et al', 'Adapted BSM Rissman et al', 'Fast approach (Mumford et al)', 'Adapted fast approach','none'};
@@ -32,7 +32,7 @@ classdef BSM<handle
             % obj.calc([1 3 6]) to indicate which SPM.mat file to calculate
             
             
-            SPMidx=[];% will contain the index to the SPMs to work on 
+            SPMidx=[];% will contain the index to the SPMs to work on
             if logical(numel(varargin))
                 SPMidx=varargin{1};
             end
@@ -52,20 +52,30 @@ classdef BSM<handle
             if numel(SPMidx)>1
                 obj.SPMIndexList=SPMidx;
                 SPMidx=obj.SPMIndexList(end);
+                try
+                    obj.Calc(SPMidx); %handle the single case
+                catch ME
+                    %if the identifier matches, just continue with next SPM
+                    if ~any(strcmpi(ME.identifier,...
+                            {'BSM:CoreCalc:SPMxBFOrder:invalid'...
+                            ,'BSM:CoreCalc:SPMSess:invalid'...
+                            }))
+                        rethrow(ME)
+                    else
+                        disp(ME.message);
+                    end
+                end
+                obj.SPMIndexList=obj.SPMIndexList(1:end-1);
+                if isempty(obj.SPMIndexList)
+                    return;
+                else
+                    obj.Calc(obj.SPMIndexList);% recursively run the rest of the list
+                end
+            else %  deal with single entry
+                obj.CoreCalc(SPMidx)
             end
-            %% start dealing with val is a single entry
-            %% do the calculation
-            %% clean up
-            %% make SPMIndexList one shorter, return if not possible
-            %% next recursion loop. 
-            warning('OFF', 'MATLAB:MKDIR:DirectoryExists');
-            %this try catch block will handle any errors that might ocure
-            %warning will not remain off by accident
-            try
-            catch ME
-                warning('ON', 'MATLAB:MKDIR:DirectoryExists');
-                rethrow(ME);
-            end
+            
+            
         end
     end
     methods %constructor and set/get methods
@@ -82,7 +92,7 @@ classdef BSM<handle
                 [val,TF]=obj.MyGetVal('Acfl',varargin);if TF;obj.Acfl=val;end
             end
             %   initialize spm job enviourment
-            spm_jobman('initcfg'); 
+            spm_jobman('initcfg');
         end
         function val=get.NumSPMs(obj)
             val=numel(obj.SPMs);
@@ -97,7 +107,7 @@ classdef BSM<handle
             obj.Type=val;
         end
         function set.Acfl(obj,val)
-            %allow clearing 
+            %allow clearing
             if isempty(val)
                 obj.Acfl=[];
             end
@@ -140,12 +150,111 @@ classdef BSM<handle
             if any(not(TF))
                 id='BSM:SetSPMs:FileNotFound';
                 msg=sprintf('file not found\t%s\n',val{not(TF)});
-                throw(MException(id,msg)); 
+                throw(MException(id,msg));
             end
             obj.SPMs=val;
         end
     end
     methods %private functions
+        function CoreCalc(obj,idx)
+            fprintf('working on :%d: %s\n',idx,obj.SPMs{idx});
+            % how to store the current status of warning and restore curent
+            WarnStat=warning;
+            warning('OFF', 'MATLAB:MKDIR:DirectoryExists');
+            %this try catch block will handle any errors that might ocure
+            %warning will not remain off by accident
+            try
+                SpmFile=obj.SPMs{idx};
+                load(SpmFile); %#ok<LOAD>
+                %% exception block
+                %NB these exception has not been tested properly by the
+                if (SPM.xBF.order ~=1 )
+                    %TestBSMClass program
+                    %throw an error. The calling function should properly
+                    %handle the error.
+                    id='BSM:CoreCalc:SPMxBFOrder:invalid';
+                    msg=sprintf('%s\n','Problem found', ...
+                        'No canonical HRF was used to model the data', ...
+                        'Current file will be skipped');
+                    throw(MException(id,msg));
+                end
+                if (length(SPM.Sess) > 1 )
+                    id='BSM:CoreCalc:SPMSess:invalid';
+                    msg=sprintf('%s\n',...
+                        'Problem found', ...
+                        'Multiple sessions in one SPM.mat not supported', ...
+                        'Current file will be skipped');
+                    throw(MException(id,msg));
+                end
+                % end exception block
+                %% set local variables
+                SPMOrig = SPM;
+                UOrig = SPM.Sess(1).U;
+                [ActCol,PasCol,AllCol]=obj.GetColDef(UOrig);
+                LocalTargetFolder = fullfile(fileparts(SpmFile),'BSM');%RR replace BSM by a obj.BSMDir so user can modify this
+                %% create directory
+                mkdir(LocalTargetFolder);
+                % loop over ActCol
+                for c=1:length(ActCol)
+                    % get current col, get other col
+                    CurCol=ActCol(c);
+                    OthCol=setdiff(1:length(ActCol),CurCol);
+                    TargetFolderCurCol=fullfile(LocalTargetFolder,sprintf('col_%04d', CurCol));
+                    for e=1:numel(UOrig(CurCol).ons)%      loop over events
+                    	U=obj.GetU(UOrig,e,c)%build U
+                    %          build SPM
+                    %          process SPM
+                    %          Cleanup
+                    end%      end loop
+                    %      pack per event result
+                    %      Cleanup
+                    
+                end % end loop act. col
+                % restore warning status
+                warning(WarnStat);
+            catch ME %turn matlab warning back on
+                warning(WarnStat);
+                rethrow(ME);
+            end
+        end
+        function U=GetU(obj,UOrig,Event,Col)
+            U=struct('name',{},'ons', [], 'dur',[], 'P',[], 'dt', [], 'u', [],'pst',[]);
+            idx=1;
+            %split out current event as first condition
+            U(idx).name{1}  = sprintf('%s_%d',UOrig(Col).name{1},Event);
+            U(idx).ons      = UOrig(Col).ons(Event);
+            U(idx).dur      = UOrig(Col).dur(Event);
+            U(idx).P        = UOrig(Col).P;
+            U(idx).dt       = UOrig(Col).dt;
+            %optional add all other events as the next condition
+            switch obj.Type
+                case {1,2} 
+                    idx = idx +1;
+                    OtherTrials=setdiff(1:numel(UOrig(Col).ons),Event);
+                    U(idx).name{1}  = sprintf('%s_oe',UOrig(Col).name{1});
+                    U(idx).ons      = UOrig(Col).ons(OtherTrials);
+                    U(idx).dur      = UOrig(Col).dur(OtherTrials);
+                    U(idx).P        = UOrig(Col).P;
+                    U(idx).dt       = UOrig(Col).dt;
+                case {3,4}
+                otherwise
+            end
+            % deal with other conditions
+            switch obj.Type
+                case {1,4} %put all other conditions in one column
+                case {2,3} %keep other conditions each in their own column
+                otherwise
+            end
+        end
+        function [ActCol,PasCol,AllCol]=GetColDef(obj,U)
+            AllCol=1:length(U);
+            if ~isempty(obj.Acfl)
+                PasCol = AllCol(obj.Acfl); %cf line 53 in spm_bsm.m
+            else
+                PasCol = [];
+            end
+            ActCol = setdiff(AllCol,PasCol);
+        end
         function set.SPMPath(obj,~)
             SPMFound=which('spm'); %check if SPM in searchpath
             if isempty(SPMFound) %SPM not found
diff --git a/resources/BSM_Class/TestBSMClass.m b/resources/BSM_Class/TestBSMClass.m
index e4580e1..71a920a 100644
--- a/resources/BSM_Class/TestBSMClass.m
+++ b/resources/BSM_Class/TestBSMClass.m
@@ -1,4 +1,6 @@
-%% This code will check the BSM class code in a very basic way. 
+%% BSM code validity check.  
+% This code will check the BSM class code in a very basic way. 
+% 
 %% create an instance
 B=BSM;
 %% 
@@ -91,4 +93,6 @@ catch ME
     end
 end
 %%
-B.Acfl=[];
\ No newline at end of file
+B.Acfl=[];
+%% Test Calc routine
+B.Calc
\ No newline at end of file