diff --git a/README.md b/README.md
index 7c5590e..21206f3 100644
--- a/README.md
+++ b/README.md
@@ -1,5 +1,8 @@
 # fwin
-A module for seismic waveform data in WIN and WIN32 formats
+A module for reading seismic waveform data in WIN and WIN32 formats
+
+## Important Notice
+This library is under being development. Significant changes in designs of module libraries might occur in future versions. 
 
 ## Compile
 
diff --git a/src/fdewin_s.f90 b/src/fdewin_s.f90
index 8256c78..9198bdd 100644
--- a/src/fdewin_s.f90
+++ b/src/fdewin_s.f90
@@ -21,7 +21,7 @@ program fdewin_s
   character(256), allocatable :: fn_win(:)
   character(4),   allocatable :: chid(:)
   integer,        allocatable :: dat(:,:), dat0(:,:)
-  integer,        allocatable :: npts(:,:), sfreq(:), npts_all(:)
+  integer,        allocatable :: npts(:,:), sfreq(:)
   character(80)               :: d_out
   integer, parameter          :: fsmax = 200
   logical                     :: is_test_mode
diff --git a/src/fwin2sac.f90 b/src/fwin2sac.f90
index 05acdca..620791b 100644
--- a/src/fwin2sac.f90
+++ b/src/fwin2sac.f90
@@ -86,6 +86,8 @@ program fwin2sac
         if( is_all_st ) call winch__get_all_stnm(ch_tbl, stnm)
       call util__read_arglst(cmpbuf, ncmp, is_all_cmp, cmpnm)
         if( is_all_cmp ) call winch__get_all_cmpnm(ch_tbl, cmpnm)
+
+      nch = 0
       do i=1, size(stnm)
         do j=1, size(cmpnm)
           !try
@@ -171,14 +173,13 @@ program fwin2sac
         call sac__write(fn_sac, sh, dat(:,i)*ch(i)%conv, .true.)
       end if
     end do
-
   end block
 
   contains
 
   subroutine usage_stop()
+
     character(18) :: sp1 = '                  '
-    character(9) :: sp2 = '         '
     write(error_unit,'(A)') 'usage: fwin2sac.x <-l listfile> '
     write(error_unit,'(A)') sp1//'[-t chtbl] [-c chids|chlist|all] [-s stnms|stlist|all] [-p cmpnm|cmplist|all]'
     stop
diff --git a/src/m_win.f90 b/src/m_win.f90
index b1c9251..8949adb 100644
--- a/src/m_win.f90
+++ b/src/m_win.f90
@@ -53,7 +53,7 @@ module m_win
   character(1),   save, private :: azero           !< binary image of zero in single-bit integer
 
 
-  integer, parameter :: YR_MIN = 1900
+  integer, parameter :: YR_MIN = 1913 !! avoid misreading 201912 as 1912
   integer, parameter :: YR_MAX = 2100
 
 contains
@@ -394,7 +394,7 @@ subroutine win__scan_buf(wh, buf)
       bs1 = 12
       bs2 = 15
     end if
-    
+
     n = 0
     !! obtain block locations & datetime information
     do