diff --git a/lib/77bit/chk77_01.f90 b/lib/77bit/chk77_01.f90
deleted file mode 100644
index 48a7fc113..000000000
--- a/lib/77bit/chk77_01.f90
+++ /dev/null
@@ -1,18 +0,0 @@
-subroutine chk77_01(msg,nwords,w,nw,i3,n3)
-
-  character*37 msg
-  character*13 w(19)
-  character*6 bcall_1,bcall_2
-  integer nw(19)
-  logical ok1,ok2
-  
-  call chkcall(w(1),bcall_1,ok1)
-  call chkcall(w(3),bcall_2,ok2)
-
-  if(nwords.eq.5 .and. trim(w(2)).eq.'RR73;' .and. ok1 .and. ok2) then
-     i3=0                             !Type 0.1: DXpedition mode
-     n3=1
-  endif
-
-  return
-end subroutine chk77_01
diff --git a/lib/77bit/t2.f90 b/lib/77bit/encode77.f90
similarity index 100%
rename from lib/77bit/t2.f90
rename to lib/77bit/encode77.f90
diff --git a/lib/77bit/hash10.f90 b/lib/77bit/hash10.f90
new file mode 100644
index 000000000..916e777c5
--- /dev/null
+++ b/lib/77bit/hash10.f90
@@ -0,0 +1,34 @@
+subroutine hash10(n10,c13,isave)
+
+  parameter (NMAX=20)
+  character*13 c13,callsign(NMAX)
+  integer ihash(NMAX)
+  logical first
+  data first/.true./
+  save first,ihash,callsign
+
+  if(first) then
+     ihash=-1
+     callsign='             '
+     first=.false.
+  endif
+
+  if(isave.ge.0) then
+     do i=1,NMAX
+        if(ihash(i).eq.n10) go to 900             !This one is already in the list
+     enddo
+     ihash(NMAX:2:-1)=ihash(NMAX-1:1:-1)
+     callsign(NMAX:2:-1)=callsign(NMAX-1:1:-1)
+     ihash(1)=n10
+     callsign(1)=c13
+  else
+     do i=1,NMAX
+        if(ihash(i).eq.n10) then
+           c13=callsign(i)
+           go to 900
+        endif
+     enddo
+  endif
+
+900 return
+end subroutine hash10
diff --git a/lib/77bit/ihashcall.f90 b/lib/77bit/ihashcall.f90
new file mode 100644
index 000000000..26d7e6721
--- /dev/null
+++ b/lib/77bit/ihashcall.f90
@@ -0,0 +1,20 @@
+integer function ihashcall(c0,m)
+
+  integer*8 n8
+  character*13 c0,c1
+  character*38 c
+  data c/' 0123456789ABCDEFGHIJKLMNOPQRSTUVWXYZ/'/
+
+  c1=c0
+  if(c1(1:1).eq.'<') c1=c1(2:)
+  i=index(c1,'>')
+  if(i.gt.0) c1(i:)='         '
+  n8=0
+  do i=1,11
+     j=index(c,c1(i:i)) - 1
+     n8=38*n8 + j
+  enddo
+  ihashcall=ishft(47055833459_8*n8,m-64)
+
+  return
+end function ihashcall
diff --git a/lib/77bit/chk77_02.f90 b/lib/77bit/pack77_02.f90
similarity index 100%
rename from lib/77bit/chk77_02.f90
rename to lib/77bit/pack77_02.f90