function [ibegu,iendu,jbegu,jendu,kbegu,kendu,...
          ibegv,iendv,jbegv,jendv,kbegv,kendv,...
          ibegw,iendw,jbegw,jendw,kbegw,kendw,...
          ibegp,iendp,jbegp,jendp,kbegp,kendp,...
          nxprocs,nyprocs,nzprocs] = read_procgrid_legacy(file)
    % [ibegu,iendu,jbegu,jendu,kbegu,kendu,...
    %  ibegv,iendv,jbegv,jendv,kbegv,kendv,...
    %  ibegw,iendw,jbegw,jendw,kbegw,kendw,...
    %  ibegp,iendp,jbegp,jendp,kbegp,kendp,...
    %  nxprocs,nyprocs,nzprocs] = read_procgrid_legacy(file)
    % Reads processor grids from 'current_proc_grid.tmp'.
    % Input
    %   file              path to 'current_proc_grid.tmp'
    % Output
    %  ibegu,iendu,jbegu,jendu,kbegu,kendu    processor grid u
    %  ibegv,iendv,jbegv,jendv,kbegv,kendv    processor grid v
    %  ibegw,iendw,jbegw,jendw,kbegw,kendw    processor grid w
    %  ibegp,iendp,jbegp,jendp,kbegp,kendp    processor grid p
    %  nxprocs,nyprocs,nzprocs                number of processors
    
    proc_grid=load(file);
    nxprocs = proc_grid(1,1);
    nyprocs = proc_grid(1,2);
    nzprocs = proc_grid(1,3);
    
    ibegu = zeros(nxprocs,1);
    iendu = zeros(nxprocs,1);
    ibegv = zeros(nxprocs,1);
    iendv = zeros(nxprocs,1);
    ibegw = zeros(nxprocs,1);
    iendw = zeros(nxprocs,1);
    ibegp = zeros(nxprocs,1);
    iendp = zeros(nxprocs,1);
    
    jbegu = zeros(nyprocs,1);
    jendu = zeros(nyprocs,1);
    jbegv = zeros(nyprocs,1);
    jendv = zeros(nyprocs,1);
    jbegw = zeros(nyprocs,1);
    jendw = zeros(nyprocs,1);
    jbegp = zeros(nyprocs,1);
    jendp = zeros(nyprocs,1);
    
    kbegu = zeros(nzprocs,1);
    kendu = zeros(nzprocs,1);
    kbegv = zeros(nzprocs,1);
    kendv = zeros(nzprocs,1);
    kbegw = zeros(nzprocs,1);
    kendw = zeros(nzprocs,1);
    kbegp = zeros(nzprocs,1);
    kendp = zeros(nzprocs,1);

    for ii=1:nxprocs
      ibegu(ii)=proc_grid(1+ii,1);
      iendu(ii)=proc_grid(1+ii,2);
      ibegv(ii)=proc_grid(1+ii,3);
      iendv(ii)=proc_grid(1+ii,4);
      ibegw(ii)=proc_grid(1+ii,5);
      iendw(ii)=proc_grid(1+ii,6);
      ibegp(ii)=proc_grid(1+ii,7);
      iendp(ii)=proc_grid(1+ii,8);
    end
    for ii=1:nyprocs
      jbegu(ii)=proc_grid(1+nxprocs+ii,1);
      jendu(ii)=proc_grid(1+nxprocs+ii,2);
      jbegv(ii)=proc_grid(1+nxprocs+ii,3);
      jendv(ii)=proc_grid(1+nxprocs+ii,4);
      jbegw(ii)=proc_grid(1+nxprocs+ii,5);
      jendw(ii)=proc_grid(1+nxprocs+ii,6);
      jbegp(ii)=proc_grid(1+nxprocs+ii,7);
      jendp(ii)=proc_grid(1+nxprocs+ii,8);
    end
    for ii=1:nzprocs
      kbegu(ii)=proc_grid(1+nxprocs+nyprocs+ii,1);
      kendu(ii)=proc_grid(1+nxprocs+nyprocs+ii,2);
      kbegv(ii)=proc_grid(1+nxprocs+nyprocs+ii,3);
      kendv(ii)=proc_grid(1+nxprocs+nyprocs+ii,4);
      kbegw(ii)=proc_grid(1+nxprocs+nyprocs+ii,5);
      kendw(ii)=proc_grid(1+nxprocs+nyprocs+ii,6);
      kbegp(ii)=proc_grid(1+nxprocs+nyprocs+ii,7);
      kendp(ii)=proc_grid(1+nxprocs+nyprocs+ii,8);
    end
end