diff --git a/gaboshlib/g_calc.sh b/gaboshlib/g_calc.sh
index d3db25d..b7ef371 100644
--- a/gaboshlib/g_calc.sh
+++ b/gaboshlib/g_calc.sh
@@ -1,66 +1,34 @@
 function g_calc {
 
+  # function for calcul
+  # $g_fd_bc_in $fd_bc_out have to be global
+
   unset g_calc_result
 
-  local g_calc_jobs g_rnd 
-  local g_bc_running=true
-  mapfile -t g_calc_jobs < <(jobs -r)
-  g_calc_jobs_v=${g_calc_jobs[*]}
-  [[ $g_calc_jobs_v =~ bc  ]] || unset g_bc_running
-
-  # Use bc in backround for multiple bc's running much faster
-  if [ -z "${g_bc_running}" ]
+  # check if bc is already running
+  if [[ -z "$g_fd_bc_in" || -z "$g_fd_bc_out" ]]
   then
-
-    g_kill_all_background_jobs bc-ql
-    g_kill_all_background_jobs sed
-
-    g_rnd=$$
-    mkdir -p ${g_tmp}/${g_rnd}
-    [ -p ${g_tmp}/${g_rnd}/bc-in ] || mkfifo ${g_tmp}/${g_rnd}/bc-in
-    [ -p ${g_tmp}/${g_rnd}/bc-out ] || mkfifo ${g_tmp}/${g_rnd}/bc-out
-    [ -p ${g_tmp}/${g_rnd}/bc-sed-in ] || mkfifo ${g_tmp}/${g_rnd}/bc-sed-in
-    [ -p ${g_tmp}/${g_rnd}/bc-sed-out ] || mkfifo ${g_tmp}/${g_rnd}/bc-sed-out
-
-    # bc stream channel
-    { bc -ql <${g_tmp}/${g_rnd}/bc-in 2>&1 >${g_tmp}/${g_rnd}/bc-out & } 2>/dev/null
-    exec 3>${g_tmp}/${g_rnd}/bc-in 4<${g_tmp}/${g_rnd}/bc-out
-
-    # sed stream channel
-    { sed -su 's/^\./0./; s/^-\./-0./' <${g_tmp}/${g_rnd}/bc-sed-in >${g_tmp}/${g_rnd}/bc-sed-out & } 2>/dev/null
-    exec 5>${g_tmp}/${g_rnd}/bc-sed-in 6<${g_tmp}/${g_rnd}/bc-sed-out
-
-    g_bc_running="true"
-  fi 
-
-  # do bc
-  echo "scale=8; $@" >&3
-  local g_bc_out
-  if ! read -t 0.1 g_bc_out <&4
+    local bc_input="$g_tmp/$$-g_bc_input"
+    local bc_output="$g_tmp/$$-g_bc_output"
+    # create fifo pipe
+    [ -p "$bc_input" ] || mkfifo "$bc_input"
+    [ -p "$bc_output" ] || mkfifo "$bc_output"
+    # run bc in background und switch i/o to pipes
+    bc -ql < "$bc_input" > "$bc_output" 2>&1 &
+    # store in filedescriptiors
+    exec {g_fd_bc_in}> "$bc_input"
+    exec {g_fd_bc_out}< "$bc_output"
+  fi
+  # send calculation and read result
+  echo "$1" >&${g_fd_bc_in}
+  read -u ${g_fd_bc_out} g_calc_result
+  g_calc_result=${g_calc_result//-./-0.}
+  g_calc_result=${g_calc_result//./0.}
+  if ! g_num_valid_number $g_calc_result
   then
-    g_traceback "$@"
-    ( exec 3<&- ) 2>/dev/null
-    ( exec 4<&- ) 2>/dev/null
-    ( exec 5<&- ) 2>/dev/null
-    ( exec 6<&- ) 2>/dev/null
-    #unset g_bc_running
-    return 1
-  fi 
-
-  # do sed
-  echo ${g_bc_out} >&5
-  local g_sed_out
-  if ! read -t 0.1 g_sed_out <&6
-  then
-    g_traceback "$@"
-    ( exec 3<&- ) 2>/dev/null
-    ( exec 4<&- ) 2>/dev/null
-    ( exec 5<&- ) 2>/dev/null
-    ( exec 6<&- ) 2>/dev/null
-    #unset g_bc_running
+    echo "${FUNCNAME} $@" 1>&2
+    unset g_calc_result
     return 1
   fi
-
-  # store result
-  g_calc_result=$g_sed_out
 }
+