diff --git a/_tools/vt100_debug/main.go b/_tools/vt100_debug/main.go
index c6036d4..9161be3 100644
--- a/_tools/vt100_debug/main.go
+++ b/_tools/vt100_debug/main.go
@@ -3,13 +3,94 @@
 package main
 
 import (
+	"bufio"
+	"bytes"
 	"fmt"
+	"io"
+	"os"
+	"os/signal"
 	"syscall"
 
 	prompt "github.com/c-bata/go-prompt"
 	"github.com/c-bata/go-prompt/internal/term"
 )
 
+type KeyPress struct {
+	Key   prompt.Key
+	Bytes []byte
+}
+
+type Parser struct {
+	Input chan rune
+	Out   chan KeyPress
+}
+
+func (p *Parser) Feed(r rune) {
+	p.Input <- r
+}
+
+func (p *Parser) Start() {
+	prefix := bytes.NewBuffer(nil)
+	retry := false
+	for {
+		if retry {
+			retry = false
+		} else {
+			in, ok := <-p.Input
+			if !ok {
+				break
+			}
+			prefix.WriteRune(in)
+		}
+
+		if prefix.Len() > 0 {
+			isPrefixOfLongerMatch := false
+			for _, s := range prompt.ASCIISequences {
+				if bytes.HasPrefix(s.ASCIICode, prefix.Bytes()) && bytes.Compare(s.ASCIICode, prefix.Bytes()) != 0 {
+					isPrefixOfLongerMatch = true
+					break
+				}
+			}
+			match := prompt.GetKey(prefix.Bytes())
+			if !isPrefixOfLongerMatch && match != prompt.NotDefined {
+				p.Out <- KeyPress{Key: match, Bytes: prefix.Bytes()}
+				prefix.Reset()
+			} else if !isPrefixOfLongerMatch && match == prompt.NotDefined {
+				found := false
+				retry = true
+
+				prefixRunes := []rune(prefix.String())
+				for i := len(prefixRunes); i > 0; i-- {
+					prefixBytes := []byte(string(prefixRunes[:i]))
+					match = prompt.GetKey(prefixBytes)
+					if match != prompt.NotDefined {
+						p.Out <- KeyPress{Key: match, Bytes: prefixBytes}
+						for j := 0; j < i; j++ {
+							_, _, _ = prefix.ReadRune()
+						}
+						found = true
+					}
+				}
+				if !found {
+					r, _, err := prefix.ReadRune()
+					if err == io.EOF {
+						continue // don't reach here.
+					}
+					p.Out <- KeyPress{Key: match, Bytes: []byte(string(r))}
+					_, _, _ = prefix.ReadRune()
+				}
+			}
+		}
+	}
+}
+
+func NewParser() *Parser {
+	return &Parser{
+		Input: make(chan rune, 1),
+		Out:   make(chan KeyPress, 1),
+	}
+}
+
 func main() {
 	if err := term.SetRaw(syscall.Stdin); err != nil {
 		fmt.Println(err)
@@ -17,31 +98,45 @@ func main() {
 	}
 	defer term.Restore()
 
-	bufCh := make(chan []byte, 128)
-	go readBuffer(bufCh)
-	fmt.Print("> ")
+	p := NewParser()
+	sigquit := make(chan os.Signal, 1)
+	signal.Notify(sigquit, syscall.SIGINT, syscall.SIGQUIT, syscall.SIGTERM)
+
+	go p.Start()
+
+	r := bufio.NewReader(os.Stdin)
+	go func() {
+		for {
+			c, _, err := r.ReadRune()
+			if err != nil {
+				if err == io.EOF {
+					break
+				} else {
+					break
+				}
+			}
+			p.Feed(c)
+		}
+		close(p.Input)
+	}()
 
 	for {
-		b := <-bufCh
-		if key := prompt.GetKey(b); key == prompt.NotDefined {
-			fmt.Printf("Key '%s' data:'%#v'\n", string(b), b)
-		} else {
-			if key == prompt.ControlC {
-				fmt.Println("exit.")
+		select {
+		case keypress := <-p.Out:
+			if keypress.Key == prompt.NotDefined {
+				fmt.Printf("Key '%s' data:'%#v'\n", string(keypress.Bytes), keypress.Bytes)
+			} else {
+				fmt.Printf("Key '%s' data:'%#v'\n", keypress.Key, keypress.Bytes)
+				if keypress.Key == prompt.ControlC {
+					return
+				}
+			}
+			if keypress.Key == prompt.ControlC {
 				return
 			}
-			fmt.Printf("Key '%s' data:'%#v'\n", key, b)
-		}
-		fmt.Print("> ")
-	}
-}
-
-func readBuffer(bufCh chan []byte) {
-	buf := make([]byte, 1024)
-
-	for {
-		if n, err := syscall.Read(syscall.Stdin, buf); err == nil {
-			bufCh <- buf[:n]
+		case <-sigquit:
+			close(p.Input)
+			return
 		}
 	}
 }
diff --git a/input.go b/input.go
index 307e747..982fc9d 100644
--- a/input.go
+++ b/input.go
@@ -96,7 +96,7 @@ var ASCIISequences = []*ASCIICode{
 	{Key: F3, ASCIICode: []byte{0x1b, 0x4f, 0x52}},
 	{Key: F4, ASCIICode: []byte{0x1b, 0x4f, 0x53}},
 
-	{Key: F1, ASCIICode: []byte{0x1b, 0x4f, 0x50, 0x41}}, // Linux console
+	{Key: F1, ASCIICode: []byte{0x1b, 0x4f, 0x5b, 0x41}}, // Linux console
 	{Key: F2, ASCIICode: []byte{0x1b, 0x5b, 0x5b, 0x42}}, // Linux console
 	{Key: F3, ASCIICode: []byte{0x1b, 0x5b, 0x5b, 0x43}}, // Linux console
 	{Key: F4, ASCIICode: []byte{0x1b, 0x5b, 0x5b, 0x44}}, // Linux console