diff --git a/modules/jtframe/src/jtutil/cmd/vcd.go b/modules/jtframe/src/jtutil/cmd/vcd.go
new file mode 100644
index 000000000..b525609f8
--- /dev/null
+++ b/modules/jtframe/src/jtutil/cmd/vcd.go
@@ -0,0 +1,68 @@
+/*
+Copyright © 2023 Jose Tejada <jose.tejada@jotego.es>
+
+*/
+package cmd
+
+import (
+	"fmt"
+	"os"
+	"bufio"
+	"jtutil/vcd"
+	"strconv"
+
+	"github.com/spf13/cobra"
+)
+
+// vcdCmd represents the vcd command
+var vcdCmd = &cobra.Command{
+	Use:   "vcd",
+	Short: "Copy all signals in a VCD file delayed by 1 frame",
+	Long: `Copy all signals in a VCD file delayed by 1 frame`,
+	Run: func(cmd *cobra.Command, args []string) {
+		runVCD()
+	},
+	Args: cobra.NoArgs,
+}
+
+func init() {
+	rootCmd.AddCommand(vcdCmd)
+
+	// Here you will define your flags and configuration settings.
+
+	// Cobra supports Persistent Flags which will work for this command
+	// and all subcommands, e.g.:
+	// vcdCmd.PersistentFlags().String("foo", "", "A help for foo")
+
+	// Cobra supports local flags which will only run when this command
+	// is called directly, e.g.:
+	// vcdCmd.Flags().BoolP("toggle", "t", false, "Help message for toggle")
+}
+
+func runVCD() {
+	const FRAME_PERIOD=16652300800
+	fin  := &vcd.LnFile{}
+	fin.Open("debug.vcd")
+	defer fin.Close()
+
+	fout, e := os.Create("delayed.vcd")
+	if e!=nil {
+		fmt.Println(e)
+		return
+	}
+	wr := bufio.NewWriter(fout)
+	defer fout.Close()
+
+	// copy all lines and
+	// modify all time stamps by subtracting a whole frame period
+	for fin.Scan() {
+		txt := fin.Text()
+		if txt!="" && txt[0]=='#' {
+			told,_ := strconv.ParseUint( txt[1:],10,64 )
+			if told!=0 { told += FRAME_PERIOD }
+			txt = fmt.Sprintf("#%d",told)
+		}
+		wr.WriteString(txt)
+		wr.WriteString("\n")
+	}
+}
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