first commit in new repo

2025-02-02 19:19:16 +01:00
commit 255137345f
10 changed files with 2009 additions and 0 deletions
--- a/README.md
+++ b/README.md
@@ -0,0 +1,124 @@
+# The PACTOR-TCP-BRIDGE
+
+<img src="pics/ptb.png" alt="logo" width="200" style="float: right">
+by Torsten Harenberg (DL1THM)
+
+## What is the PACTOR-TCP-BRIDGE (ptb)
+
+It's a tool that
+
+- talks via a serial line (USB or Bluetooth) to [PACTOR modems](https://scs-ptc.com/modems.html) made by [SCS](https://scs-ptc.com) using the extended WA8DED hostmode [(see the manual, chapter 10)](https://www.p4dragon.com/download/SCS_Manual_PTC-IIIusb_4.1.pdf) protocol these modems offer
+- offers two TCP sockets which can be used by [Pat](https://getpat.io/) (and other tools)
+
+## What it is used for
+
+The main purpose is to build a connection between Pat and PACTOR modems. In order to establish a "listen" mode for PACTOR in Pat,
+the modem needs to be kept in the WA8DED hostmode. I found it easiest to create a separate program 
+for that - in the same way, the VARA modem is a separate program.
+
+On the long run, this tool will replace the current PACTOR driver in Pat.
+
+## How to use it
+
+In order to use this tool, you'll need to configure it.
+
+If you start it for the first time, it will create a default configuration file and will tell you its location:
+
+```bash
+ % ./ptb 
+new Config file /Users/harenber/.config/dl1thm.pactortcpbridge/Config.yaml created. Please edit the Config file and restart the application
+```
+
+Now edit the file and configure it accordingly:
+
+```yaml
+device: /tmp/ttyUSB0
+baudrate: 9600
+mycall: N0CALL
+server_address: 127.0.0.1:8300
+data_address: 127.0.0.1:8301
+cmdline_init: ""
+vara_mode: false
+```
+
+| Variable          | Meaning                                                                                                                     |
+|-------------------|-----------------------------------------------------------------------------------------------------------------------------|
+| `device`          | Path to the serial device where the modem is connected                                                                      |
+| `baudrate`        | baud rate of the modem                                                                                                      |
+| `mycall`          | The callsign to be used on HF                                                                                               |
+| `server_address`  | server socket address for the **commands**                                                                                  |
+| `data_address`    | server socket address for the **data**                                                                                      |
+| `cmdline_init`    | extra commands sent to the modem before going into hostmode, separated by semicolons, Ex: `DISP BR 1;DISP A 1;DISP DIMMOFF` |
+| `vara_mode`       | see the chapter about the VARA mode                                                                                         |
+
+If you plan to you Pat with the VARA driver, data `data_address` you **must** use a port number one number higher than the `server_address`.
+
+A matching Pat config using VARA for the example above would look like:
+
+```yaml
+"varahf": {
+"addr": "localhost:8300",
+"bandwidth": 2300,
+"rig": "",
+"ptt_ctrl": false
+}
+```
+
+Using PACTOR, the PTT is triggered through the modem, so you need to set `ptt_ctrl` to `false`! If you configure a `rig`, it 
+needs to be connected in a way that `rigctl` can configure it. Configure your rig through the PACTOR modem
+is **not** supported in VARA mode.
+
+## VARA mode 
+
+The VARA mode translate WA8DED commands into VARA commands and vice versa. See the VARA homepage for the "VARA TNC Commands"
+doumentation. 
+
+If enabledm software which is written to interact with the VARA software TNC to work
+with PACTOR as well. It was used by the author to use the [VARA driver for Pat](https://github.com/n8jja/Pat-Vara)
+with the PACTOR-TCP-Bridge.
+
+## How to run
+
+As a rule of thumb, you have to start the PACTOR-TCP-bridge before you want to use
+Pat and stop it after you finished using Pat. 
+
+So a typical session works like this
+
+1. start the PACTOR-TCP-Bridge
+2. wait for it to finish configure your modem
+3. use Pat (or any other software)
+4. quit Pat
+5. stop the PACTOR-TCP-Bridge
+
+The software supports command line options:
+
+```bash
+ % ./ptb --help
+Usage of ptb - the PACTOR-IP-Bridge:
+  -c, --configfile string   Name of config file (default "Config.yaml")
+  -d, --daemon              Daemon mode (no TUI)
+  -l, --logfile string      Path to the log file (default "/tmp/pactortcpbridge.log")
+```
+
+which should be rather self-explaining.
+
+A typical session (without using the daemon mode, see below) looks like this:
+
+![Screenshot showing a terminal with a session](pics/Screenshot.png)
+
+- on the upper left you will see all **payload** from and to the PACTOR modem
+- on the lower left the **commands** (with VARA translations, if switched on) to and **answers** from the modem
+- on the right hand side you'll see a clock, then a mode indicator (showing `VARA` or `TCP`). Furthermore, you'll see two indicator (`TCP CMD` and `TCP DATA`) which will turn green when a client is connected. The 4 counters below show the usage of the buffers.
+
+
+## "Daemon"-mode
+
+The "daemon"-mode will omit the terminal UI ("TUI") and might be useful if you have no full terminal (or to run the tool with systemd).
+
+Instead of the UI, you will only see a message saying that you may quit with CTRL-C.
+
+## Keys 
+
+- **CTRL-C**<br />Quits the program
+- **CTRL-V**<br />swtiches between the VARA and normal mode
+
--- a/TODO.txt
+++ b/TODO.txt
@@ -0,0 +1,15 @@
+--Kein leeren Befehl senden--
+-- Keine leere Antwort durch parsen --
+-- VARA Tests --
+-- CLI --
+-- Debug handling --
+-- Muell vom Input ausschliessen? --
+-- kommen error Mmeldungen durch? -> ja --
+stophostmodem(): Timeouts beim lesen vom Modem... (scheint weg zu sein?)
+-- Was mache ich mit dem initfile --
+Log sollte auch auf stdout schreiben
+-- VARA Mode beim starten --
+-- Goconcurrentqueue los werden --
+-- "daemon" mode: Achtung.. Daten fuer den Screen werden wahrscheinlich noch geschickt. ERLEDIGT --
+-- Vielleicht flags umstellen auf Standard-Flags mit short forms wie hier beschrieben https://www.antoniojgutierrez.com/posts/2021-05-14-short-and-long-options-in-go-flags-pkg/ --
+
--- a/fifo.go
+++ b/fifo.go
@@ -0,0 +1,241 @@
+package main
+
+import (
+	"context"
+	"errors"
+	"sync"
+)
+
+type ByteFIFO struct {
+	buffer []byte     // The underlying byte slice
+	mutex  sync.Mutex // Mutex for thread safety
+	cond   *sync.Cond // Condition variable for signaling
+	cap    int        // Capacity of the buffer
+}
+
+// NewByteFIFO creates a new ByteFIFO with the given capacity.
+func NewByteFIFO(capacity int) *ByteFIFO {
+	fifo := &ByteFIFO{
+		buffer: make([]byte, 0, capacity),
+		cap:    capacity,
+	}
+	fifo.cond = sync.NewCond(&fifo.mutex) // Initialize condition variable
+	return fifo
+}
+
+// Enqueue adds bytes to the end of the buffer. Returns an error if the buffer is full.
+func (f *ByteFIFO) Enqueue(data []byte) error {
+	f.mutex.Lock()
+	defer f.mutex.Unlock()
+
+	if len(f.buffer)+len(data) > f.cap {
+		return errors.New("buffer overflow")
+	}
+
+	f.buffer = append(f.buffer, data...)
+	f.cond.Signal() // Notify waiting goroutines that data is available
+	return nil
+}
+
+// Dequeue removes and returns the first `n` bytes from the buffer (or what's left if n>len(f.buffer)).
+// Returns an error if nothing is in the queue
+func (f *ByteFIFO) Dequeue(n int) ([]byte, error) {
+	f.mutex.Lock()
+	defer f.mutex.Unlock()
+
+	if len(f.buffer) == 0 {
+		return nil, errors.New("buffer is empty")
+	}
+	if n > len(f.buffer) {
+		n = len(f.buffer)
+	}
+
+	data := f.buffer[:n]
+	f.buffer = f.buffer[n:]
+	return data, nil
+}
+
+// DequeueOrWait removes and returns the first `n` bytes, waiting if the buffer is empty until data is available.
+func (f *ByteFIFO) DequeueOrWait(n int) ([]byte, error) {
+	f.mutex.Lock()
+	defer f.mutex.Unlock()
+
+	// Wait until enough data is available
+	for len(f.buffer) < n {
+		f.cond.Wait()
+	}
+
+	data := f.buffer[:n]
+	f.buffer = f.buffer[n:]
+	return data, nil
+}
+
+// DequeueOrWaitContext removes and returns the first `n` bytes, waiting if necessary until data is available or the context is canceled.
+func (f *ByteFIFO) DequeueOrWaitContext(ctx context.Context, n int) ([]byte, error) {
+	done := make(chan struct{})
+	var data []byte
+	var err error
+
+	go func() {
+		f.mutex.Lock()
+		defer f.mutex.Unlock()
+		defer close(done)
+
+		// Wait until enough data is available
+		for len(f.buffer) < n {
+			select {
+			case <-ctx.Done():
+				err = ctx.Err()
+				return
+			default:
+				f.cond.Wait()
+			}
+		}
+
+		data = f.buffer[:n]
+		f.buffer = f.buffer[n:]
+	}()
+
+	select {
+	case <-done:
+		return data, err
+	case <-ctx.Done():
+		return nil, ctx.Err()
+	}
+}
+
+// Peek returns the first `n` bytes without removing them from the buffer. Returns an error if there are not enough bytes.
+func (f *ByteFIFO) Peek(n int) ([]byte, error) {
+	f.mutex.Lock()
+	defer f.mutex.Unlock()
+
+	if n > len(f.buffer) {
+		return nil, errors.New("not enough data in buffer")
+	}
+
+	return f.buffer[:n], nil
+}
+
+// Size returns the current number of bytes in the buffer.
+func (f *ByteFIFO) GetLen() int {
+	f.mutex.Lock()
+	defer f.mutex.Unlock()
+
+	return len(f.buffer)
+}
+
+// Capacity returns the maximum capacity of the buffer.
+func (f *ByteFIFO) Capacity() int {
+	return f.cap
+}
+
+// *****
+
+type StringFIFO struct {
+	buffer []string   // The underlying byte slice
+	mutex  sync.Mutex // Mutex for thread safety
+	cond   *sync.Cond // Condition variable for signaling
+}
+
+// NewByteFIFO creates a new ByteFIFO with the given capacity.
+func NewStringFIFO() *StringFIFO {
+	fifo := &StringFIFO{
+		buffer: make([]string, 0),
+	}
+	fifo.cond = sync.NewCond(&fifo.mutex) // Initialize condition variable
+	return fifo
+}
+
+// Enqueue adds a string to the end of the buffer. Returns an error if the buffer is full.
+func (f *StringFIFO) Enqueue(data string) error {
+	f.mutex.Lock()
+	defer f.mutex.Unlock()
+
+	f.buffer = append(f.buffer, data)
+	f.cond.Signal() // Notify waiting goroutines that data is available
+	return nil
+}
+
+// Dequeue removes and returns the first `n` bytes from the buffer (or what's left if n>len(f.buffer)).
+// Returns an error if nothing is in the queue
+func (f *StringFIFO) Dequeue() (string, error) {
+	f.mutex.Lock()
+	defer f.mutex.Unlock()
+
+	if len(f.buffer) == 0 {
+		return "", errors.New("buffer is empty")
+	}
+
+	data := f.buffer[0]
+	f.buffer = f.buffer[1:]
+	return data, nil
+}
+
+// DequeueOrWait removes and returns the first `n` bytes, waiting if the buffer is empty until data is available.
+func (f *StringFIFO) DequeueOrWait() (string, error) {
+	f.mutex.Lock()
+	defer f.mutex.Unlock()
+
+	// Wait until enough data is available
+	for len(f.buffer) == 0 {
+		f.cond.Wait()
+	}
+
+	data := f.buffer[0]
+	f.buffer = f.buffer[1:]
+	return data, nil
+}
+
+// DequeueOrWaitContext removes and returns the first `n` bytes, waiting if necessary until data is available or the context is canceled.
+func (f *StringFIFO) DequeueOrWaitContext(ctx context.Context) (string, error) {
+	done := make(chan struct{})
+	var data string
+	var err error
+
+	go func() {
+		f.mutex.Lock()
+		defer f.mutex.Unlock()
+		defer close(done)
+
+		// Wait until enough data is available
+		for len(f.buffer) == 0 {
+			select {
+			case <-ctx.Done():
+				err = ctx.Err()
+				return
+			default:
+				f.cond.Wait()
+			}
+		}
+
+		data = f.buffer[0]
+		f.buffer = f.buffer[1:]
+	}()
+
+	select {
+	case <-done:
+		return data, err
+	case <-ctx.Done():
+		return "", ctx.Err()
+	}
+}
+
+// Peek returns the first `n` bytes without removing them from the buffer. Returns an error if there are not enough bytes.
+func (f *StringFIFO) Peek() (string, error) {
+	f.mutex.Lock()
+	defer f.mutex.Unlock()
+
+	if len(f.buffer) == 0 {
+		return "", errors.New("not enough data in buffer")
+	}
+
+	return f.buffer[0], nil
+}
+
+// GetLen returns the current number of bytes in the buffer.
+func (f *StringFIFO) GetLen() int {
+	f.mutex.Lock()
+	defer f.mutex.Unlock()
+
+	return len(f.buffer)
+}
--- a/go.mod
+++ b/go.mod
@@ -0,0 +1,23 @@
+module gotests/pactorjarabridge
+
+go 1.23
+
+require (
+	github.com/TwiN/go-color v1.4.1
+	github.com/albenik/go-serial/v2 v2.6.1
+	github.com/howeyc/crc16 v0.0.0-20171223171357-2b2a61e366a6
+	github.com/jroimartin/gocui v0.5.0
+	github.com/karanveersp/store v0.0.0-20230714152426-8bd691c2bad8
+	gopkg.in/yaml.v2 v2.4.0
+)
+
+require (
+	github.com/BurntSushi/toml v1.2.1 // indirect
+	github.com/creack/goselect v0.1.2 // indirect
+	github.com/kr/pretty v0.3.1 // indirect
+	github.com/mattn/go-runewidth v0.0.9 // indirect
+	github.com/nsf/termbox-go v1.1.1 // indirect
+	go.uber.org/atomic v1.10.0 // indirect
+	go.uber.org/multierr v1.9.0 // indirect
+	golang.org/x/sys v0.20.0 // indirect
+)
--- a/main.go
+++ b/main.go
@@ -0,0 +1,192 @@
+package main
+
+import (
+	"errors"
+	"flag"
+	"fmt"
+	"path/filepath"
+
+	//log "github.com/fangdingjun/go-log"
+	"log"
+	"os"
+	"os/signal"
+	"syscall"
+
+	"github.com/jroimartin/gocui"
+	"github.com/karanveersp/store"
+	"gopkg.in/yaml.v2"
+)
+
+const usage = `Usage of ptb - the PACTOR-IP-Bridge:
+  -c, --configfile string   Name of config file (default "Config.yaml")
+  -d, --daemon              Daemon mode (no TUI)
+  -l, --logfile string      Path to the log file
+`
+
+const (
+	StatusTCPCmdActive  uint8 = 1 << iota //00000001
+	StatusTCPDataActive                   //00000010
+)
+
+type TCPServer struct {
+	Protocol   chan string
+	ToPactor   *ByteFIFO
+	FromPactor *ByteFIFO
+	VARAMode   bool
+	DaemonMode bool
+	Status     uint8
+	Command    struct {
+		Cmd      *StringFIFO
+		Response *StringFIFO
+	}
+	Data struct {
+		Data     *ByteFIFO
+		Response *ByteFIFO
+	}
+}
+
+func NewTCPServer(varamode bool, daemonmode bool) *TCPServer {
+	return &TCPServer{
+		Protocol:   make(chan string, 1024),
+		ToPactor:   NewByteFIFO(1024),
+		FromPactor: NewByteFIFO(1024),
+		VARAMode:   varamode,
+		DaemonMode: daemonmode,
+		Status:     0,
+		Command: struct {
+			Cmd      *StringFIFO
+			Response *StringFIFO
+		}{Cmd: NewStringFIFO(), Response: NewStringFIFO()},
+		Data: struct {
+			Data     *ByteFIFO
+			Response *ByteFIFO
+		}{Data: NewByteFIFO(10240), Response: NewByteFIFO(10240)},
+	}
+}
+
+type Userconfig struct {
+	Device            string `yaml:"device"`
+	Baudrate          int    `yaml:"baudrate"`
+	Mycall            string `yaml:"mycall"`
+	ServerAddress     string `yaml:"server_address"`
+	DataAddress       string `yaml:"data_address"`
+	CmdLineInit       string `yaml:"cmdline_init"`
+	StartwithVaraMode bool   `yaml:"vara_mode"`
+}
+
+func configmanage(Config *Userconfig, path string) error {
+	cf := store.GetApplicationDirPath() + string(os.PathSeparator) + path
+
+	_, err := os.Stat(cf)
+	if err != nil {
+		log.Println("loadConfig error:", err)
+		log.Println("Config file not found. Creating new one")
+		Config = &Userconfig{Device: "/tmp/ttyUSB0",
+			Baudrate:          9600,
+			Mycall:            "N0CALL",
+			ServerAddress:     "127.0.0.1:8300",
+			DataAddress:       "127.0.0.1:8301",
+			CmdLineInit:       "",
+			StartwithVaraMode: false}
+
+		if err := store.Save("Config.yaml", Config); err != nil {
+			log.Println("failed to save the Config file: ", err)
+			return err
+		}
+		return errors.New(fmt.Sprintf("new Config file %s created. Please edit the Config file and restart the application", cf))
+
+	}
+	if err := store.Load(path, Config); err != nil {
+		return err
+	}
+
+	if Config.Device != "" {
+		//log.Println("Config loaded:", Config)
+		return nil
+	}
+	return errors.New(fmt.Sprintf("Empty device name in Config file. Please edit the Config file %s and restart the application", cf))
+}
+
+func init() {
+	store.Init("dl1thm.pactortcpbridge")
+	store.Register("ini", yaml.Marshal, yaml.Unmarshal)
+}
+
+var s *TCPServer // s is a pointer to TCPServer, managing communication via channels and FIFO queues for command and data handling.
+
+func main() {
+
+	tmpfile := filepath.FromSlash(os.TempDir() + "/ptb.log")
+
+	// read command line arguments -- the standard flag module unfortunately doesn't know shorthands
+	var configfile string
+	flag.StringVar(&configfile, "configfile", "Config.yaml", "Name of config file")
+	flag.StringVar(&configfile, "c", "Config.yaml", "Name of config file")
+	var logfile string
+	flag.StringVar(&logfile, "logfile", tmpfile, "Name of log file")
+	flag.StringVar(&logfile, "l", tmpfile, "Name of log file")
+	var daemonMode bool
+	flag.BoolVar(&daemonMode, "daemon", false, "Daemon mode (no TUI)")
+	flag.BoolVar(&daemonMode, "d", false, "Daemon mode (no TUI)")
+	flag.Usage = func() { fmt.Print(usage) }
+
+	flag.Parse()
+
+	f, err := os.OpenFile(logfile, os.O_RDWR|os.O_CREATE|os.O_APPEND, 0666)
+	if err != nil {
+		log.Fatalf("error opening file: %v", err)
+	}
+	defer f.Close()
+
+	log.SetOutput(f)
+	fmt.Println("logging to " + logfile)
+
+	// read config
+	var Config Userconfig
+	//c := store.GetApplicationDirPath()
+	err = configmanage(&Config, configfile)
+	if err != nil {
+		fmt.Println(err)
+		os.Exit(1)
+	}
+
+	s = NewTCPServer(Config.StartwithVaraMode, daemonMode)
+	fmt.Println("Initializing PACTOR modem, please wait...")
+	m, err := OpenModem(Config.Device, Config.Baudrate, Config.Mycall, "", Config.CmdLineInit)
+	if err != nil {
+		log.Panicln(err)
+	}
+	defer m.Close()
+
+	go tcpCmdServer(&Config)
+	go tcpDataServer(&Config)
+
+	if !daemonMode {
+		// Initialize the gocui GUI
+		g, err := gocui.NewGui(gocui.OutputNormal)
+		if err != nil {
+			log.Panicln(err)
+		}
+		defer g.Close()
+
+		g.SetManagerFunc(layout)
+		go protocolUpdate(g)
+		go pactorUpdate(g)
+		go statusUpdate(g)
+
+		// Set keybindings
+		if err := keybindings(g); err != nil {
+			log.Panicln(err)
+		}
+		// Start the main TUI loop
+		if err := g.MainLoop(); err != nil && err != gocui.ErrQuit {
+			log.Panicln(err)
+		}
+	} else {
+		// daemon mode: just print a message and wait for CTRL-C
+		done := make(chan os.Signal, 1)
+		signal.Notify(done, syscall.SIGINT, syscall.SIGTERM)
+		fmt.Println("pactortcpbridge running, press ctrl+c to end the process...")
+		<-done
+	}
+}
--- a/pics/Screenshot.png
+++ b/pics/Screenshot.png
--- a/pics/ptb.png
+++ b/pics/ptb.png
--- a/ptc.go
+++ b/ptc.go
@@ -0,0 +1,937 @@
+package main
+
+import (
+	"bufio"
+	"bytes"
+	"encoding/binary"
+	"encoding/hex"
+	"errors"
+	"fmt"
+	"github.com/TwiN/go-color"
+	"github.com/albenik/go-serial/v2"
+	"log"
+	"math/bits"
+	"os"
+	"regexp"
+	"runtime"
+	"strconv"
+	"strings"
+	"sync"
+	"time"
+
+	"github.com/howeyc/crc16"
+)
+
+var SCSversion = map[string]string{
+	"A": "PTC-II",
+	"B": "PTC-IIpro",
+	"C": "PTC-IIe",
+	"D": "PTC-IIex",
+	"E": "PTC-IIusb",
+	"F": "PTC-IInet",
+	"H": "DR-7800",
+	"I": "DR-7400",
+	"K": "DR-7000",
+	"L": "PTC-IIIusb",
+	"T": "PTC-IIItrx",
+}
+
+type pflags struct {
+	exit      bool
+	stopmodem bool
+	//disconnected chan struct{}
+	connected    chan struct{}
+	closeWaiting chan struct{}
+}
+
+type pmux struct {
+	device sync.Mutex
+	pactor sync.Mutex
+	write  sync.Mutex
+	read   sync.Mutex
+	close  sync.Mutex
+	bufLen sync.Mutex
+	//	sendbuf sync.Mutex
+	//	recvbuf sync.Mutex
+}
+
+type Modem struct {
+	devicePath string
+
+	localAddr  string
+	remoteAddr string
+
+	state State
+
+	device     *serial.Port
+	mux        pmux
+	wg         sync.WaitGroup
+	flags      pflags
+	goodChunks int
+	//	recvBuf       bytes.Buffer
+	//	cmdBuf        chan string
+	//	sendBuf       bytes.Buffer
+	packetcounter bool
+	chanbusy      bool
+	cmdlineinit   string
+	initfile      string
+	closeOnce     sync.Once
+}
+
+const (
+	SerialTimeout = 1
+	PactorChannel = 4
+	MaxSendData   = 255
+	MaxFrameNotTX = 2
+)
+
+// ToPactor states
+const (
+	Closed State = iota
+	Ready
+	Connecting
+	Conntected
+)
+
+type State uint8
+
+//var debugMux sync.Mutex
+
+func debugEnabled() int {
+	if value, ok := os.LookupEnv("PACTOR_DEBUG"); ok {
+		level, err := strconv.Atoi(value)
+		if err == nil {
+			return level
+		}
+	}
+	return 0
+}
+
+func writeDebug(message string, level int) {
+	//debugMux.Lock()
+	//	defer debugMux.Unlock()
+	if debugEnabled() >= level {
+		_, file, no, ok := runtime.Caller(1)
+		if ok {
+			log.Println(file + "#" + strconv.Itoa(no) + ": " + message)
+		} else {
+			log.Println(message)
+		}
+	}
+	return
+}
+
+// OpenModem: Initialise the pactor modem and all variables. Switch the modem into hostmode.
+//
+// Will abort if modem reports failed link setup, Close() is called or timeout
+// has occured (90 seconds)
+func OpenModem(path string, baudRate int, myCall string, initfile string, cmdlineinit string) (p *Modem, err error) {
+	writeDebug("Trying to open "+path+" with "+strconv.Itoa(baudRate)+" baud.", 0)
+	p = &Modem{
+		// Initialise variables
+		devicePath: path,
+
+		localAddr:  myCall,
+		remoteAddr: "",
+
+		state: Closed,
+
+		device: nil,
+		flags: pflags{
+			exit:         false,
+			stopmodem:    false,
+			connected:    make(chan struct{}, 1),
+			closeWaiting: make(chan struct{}, 1)},
+		goodChunks: 0,
+		//	cmdBuf:       make(chan string, 0),
+		cmdlineinit: cmdlineinit,
+		initfile:    initfile,
+	}
+
+	writeDebug("Initialising pactor modem", 1)
+	if err := p.checkSerialDevice(); err != nil {
+		writeDebug(err.Error(), 1)
+		return nil, err
+	}
+
+	//Setup serial device
+	if p.device, err = serial.Open(p.devicePath, serial.WithBaudrate(baudRate), serial.WithReadTimeout(SerialTimeout)); err != nil {
+		writeDebug(err.Error(), 1)
+		return nil, err
+	}
+
+	err = p.init()
+	if err != nil {
+		return nil, err
+	}
+	// run modem thread
+
+	time.Sleep(3 * time.Second) // give the device a moment to settle, so no commands get lost
+	return p, nil
+}
+
+func (p *Modem) setState(state State) {
+	writeDebug("Setting state to: "+strconv.FormatUint(uint64(state), 10), 1)
+	p.state = state
+}
+
+func (p *Modem) IsClosed() bool {
+	if p == nil {
+		return true
+	}
+	return p.state == Closed
+}
+
+func (p *Modem) init() (err error) {
+	writeDebug("Entering PACTOR init", 1)
+	// Get modem out of CRC hostmode if it is still in it while starting.
+	//p.stophostmode()
+	//p._write(string([]byte{0xaa, 0xaa, 0x00, 0x01, 0x05, 0x4a, 0x48, 0x4f, 0x53, 0x54, 0x30, 0xfb, 0x3d}))
+	//time.Sleep(100 * time.Millisecond)
+	//_, _, _ = p._read(100)
+
+	if _, _, err = p.writeAndGetResponse("", -1, false, 10240); err != nil {
+		return err
+	}
+
+	// Make sure, modem is in main menu. Will respose with "ERROR:" when already in it -> Just discard answer!
+	_, ans, err := p.writeAndGetResponse("Quit", -1, false, 1024)
+	if err != nil {
+		return err
+	}
+
+	if len(ans) < 2 {
+		return errors.New("Modem does not react to Quit command. Please re-power your modem")
+	}
+
+	// Check if we can determine the modem's type
+	_, ver, err := p.writeAndGetResponse("ver ##", -1, false, 1024)
+	if err != nil {
+		return err
+	}
+	re, err := regexp.Compile(`\w#1`)
+	if err != nil {
+		return errors.New("Cannot read SCS modem version string, did you configure the correct serial device? Error: " + err.Error())
+	}
+	version := strings.ReplaceAll(string(re.Find([]byte(ver))), "#1", "")
+	modem, exists := SCSversion[version]
+
+	if !exists {
+		return errors.New("Found a modem type: " + ver + " which this driver doesn't support. Please contact the author.")
+	}
+	writeDebug("Found a "+modem+" modem at "+p.devicePath, 0)
+	writeDebug("Running init commands", 1)
+	ct := time.Now()
+	commands := []string{"DD", "RESTART", "MYcall " + p.localAddr, "PTCH " + strconv.Itoa(PactorChannel),
+		"MAXE 35", "REM 0", "CHOB 0", "PD 1",
+		"ADDLF 0", "ARX 0", "BELL 0", "BC 0", "BKCHR 25", "CMSG 0", "LFIGNORE 0", "LISTEN 0", "MAIL 0", "REMOTE 0",
+		"PDTIMER 5", "STATUS 1",
+		"TONES 4", "MARK 1600", "SPACE 1400", "CWID 0", "CONType 3", "MODE 0",
+		"DATE " + ct.Format("020106"), "TIME " + ct.Format("150405")}
+
+	//run additional commands provided on the command line with "init"
+	if p.cmdlineinit != "" {
+		for _, command := range strings.Split(strings.TrimSuffix(p.cmdlineinit, "\n"), ";") {
+			commands = append(commands, command)
+		}
+	}
+
+	for _, cmd := range commands {
+		var res string
+		writeDebug("Sending command to modem: "+cmd, 0)
+		_, res, err = p.writeAndGetResponse(cmd, -1, false, 1024)
+		if err != nil {
+			return err
+		}
+		if strings.Contains(res, "ERROR") {
+			log.Print(`Command "` + cmd + `" not accepted: ` + res)
+			return fmt.Errorf(`Command "` + cmd + `" not accepted: ` + res)
+		} else {
+			l := fmt.Sprintf("%s --> "+color.InGreen("OK\n"), cmd) // print some output
+			log.Println(l)
+			fmt.Println(l)
+		}
+	}
+
+	// run additional commands stored in the init script file
+	if p.initfile != "" {
+		if err = p.runInitScript(p.initfile); err != nil {
+			return err
+		}
+	}
+	p.flags.stopmodem = false
+	p.setState(Ready)
+	go p.modemThread()
+	//p.flags.exit = false
+	return nil
+}
+
+// Send additional initialisation command stored in the InitScript
+//
+// Each command has to be on a new line
+func (p *Modem) runInitScript(initScript string) error {
+	if _, err := os.Stat(initScript); os.IsNotExist(err) {
+		return fmt.Errorf("ERROR: PTC init script defined but not existent: %s", initScript)
+	}
+
+	file, err := os.Open(initScript)
+	if err != nil {
+		return err
+	}
+	defer file.Close()
+
+	scanner := bufio.NewScanner(file)
+	for scanner.Scan() {
+		writeDebug("Sending command to modem: "+scanner.Text(), 0)
+		if _, _, err = p.writeAndGetResponse(scanner.Text(), -1, false, 1024); err != nil {
+			return err
+		}
+	}
+
+	if err := scanner.Err(); err != nil {
+		return err
+	}
+
+	return nil
+}
+
+func (p *Modem) modemThread() {
+	writeDebug("start modem thread", 1)
+
+	_, _, _ = p.read(1024)
+	_, _, _ = p.writeAndGetResponse("JHOST4", -1, false, 1024)
+	_, _, _ = p.read(1024)
+	// need to wait a second for WA8DED mode to "settle"
+	time.Sleep(time.Second)
+	const chunkSize = 1024
+	p.wg.Add(1)
+	for !p.flags.stopmodem {
+
+		// TX data
+		if p.getNumFramesNotTransmitted() < MaxFrameNotTX {
+			//				data := p.getSendData()
+			data, err := s.Data.Data.Dequeue(256)
+			if err == nil {
+				//data := []byte(d.(string))
+				writeDebug("Write data ("+strconv.Itoa(len(data))+"): "+hex.EncodeToString(data), 2)
+				// TODO: Catch errors!
+				_, _, _ = p.writeAndGetResponse(string(data), PactorChannel, false, chunkSize)
+				time.Sleep(1000 * time.Millisecond) // wait for the data to be filled into the buffer
+
+				if s.VARAMode {
+					s.Command.Response.Enqueue(fmt.Sprintf("BUFFER %d", s.Data.Data.GetLen()))
+				}
+
+			}
+		}
+
+		// TX commands
+		cmd, err := s.Command.Cmd.Dequeue()
+		if err == nil {
+			writeDebug("Write command ("+strconv.Itoa(len(cmd))+"): "+cmd, 1)
+			_, ans, err := p.writeAndGetResponse(cmd, PactorChannel, true, chunkSize)
+			if err != nil {
+				writeDebug("Error when sending Command: "+err.Error(), 0)
+			}
+			if strings.HasPrefix(cmd, "C ") || strings.HasPrefix(cmd, "c ") {
+
+				// in VARA mode we need to know if the connection is outgoing or incoming so mark outgoing connects
+				p.setState(Connecting)
+			}
+			if len(ans) > 2 {
+				if !s.VARAMode {
+					s.Command.Response.Enqueue(ans[2:])
+				}
+			}
+			writeDebug("Answer from modem: "+ans, 1)
+			// TODO: Catch errors!
+		}
+
+		// RX
+		var res []byte
+
+		if channels, err := p.getChannelsWithOutput(); err == nil {
+			for _, c := range channels {
+				_, data, _ := p.writeAndGetResponse("G", c, true, chunkSize)
+				if _, res, err = p.checkResponse(data, c); err != nil {
+					writeDebug("checkResponse returned: "+err.Error(), 1)
+				} else {
+					if res != nil {
+						writeDebug("response: "+string(res)+"\n"+hex.Dump(res), 3)
+						switch c {
+						case PactorChannel:
+							s.Data.Response.Enqueue(res)
+							writeDebug("Written to sendbuf", 3)
+						case 254: //Status update
+							p.chanbusy = int(res[0])&112 == 112 // See PTC-IIIusb manual "STATUS" command
+							writeDebug("PACTOR state: "+strconv.FormatInt(int64(res[0]), 2), 2)
+						default:
+							writeDebug("Channel "+strconv.Itoa(c)+": "+string(res), 1)
+						}
+					}
+				}
+			}
+		}
+	}
+	time.Sleep(100 * time.Millisecond)
+
+	_, _, err := p.writeAndGetResponse("JHOST0", PactorChannel, true, chunkSize)
+	if err != nil {
+		writeDebug("PACTOR ERROR Could not get modem out of the WA8DED mode: "+err.Error(), 0)
+	}
+
+	writeDebug("Modemthread is about to end", 1)
+
+	time.Sleep(100 * time.Millisecond)
+	p.wg.Done()
+	//p.ModemClose()
+	writeDebug("exit modem thread", 1)
+}
+
+func (p *Modem) Close() error {
+	_, file, no, ok := runtime.Caller(1)
+	if ok {
+		writeDebug("PACTOR Close called from "+file+"#"+strconv.Itoa(no), 1)
+	} else {
+		writeDebug("PACTOR Close called", 1)
+	}
+
+	var err error
+	p.closeOnce.Do(func() { err = p.close() })
+	return err
+}
+
+func (p *Modem) stophostmode() {
+	writeDebug("Stopping WA8DED hostmode", 0)
+	var ok bool
+	var err error
+
+	// Send JHOST0 in CRC-enhanced WA8DED mode syntax
+
+	for ok == false {
+		buff := make([]byte, 100)
+		p.device.Write([]byte{0xaa, 0xaa, 0x00, 0x01, 0x05, 0x4a, 0x48, 0x4f, 0x53, 0x54, 0x30, 0xfb, 0x3d})
+		time.Sleep(100 * time.Millisecond)
+		for {
+			n, err := p.device.Read(buff)
+			if err != nil {
+				log.Fatal(err)
+				break
+			}
+			if n == 0 {
+				break
+			}
+			//fmt.Printf("%v", string(buff[:n]))
+		}
+		p.device.Write([]byte("\rRESTART\r"))
+		time.Sleep(1000 * time.Millisecond)
+		for {
+			n, err := p.device.Read(buff)
+			if err != nil {
+				log.Fatal(err)
+				break
+			}
+			if n == 0 {
+				break
+			}
+			//fmt.Printf("%v", string(buff[:n]))
+		}
+		ok, err = regexp.Match("cmd:", buff)
+		if err != nil {
+			writeDebug("Error in stophostmode: "+err.Error(), 0)
+		}
+	}
+}
+
+// Wait for transmission to be finished
+//
+// BLOCKING until either all frames are transmitted and acknowledged or timeouts
+// occurs
+func (p *Modem) waitTransmissionFinish(t time.Duration) error {
+	timeout := time.After(t)
+	tick := time.Tick(500 * time.Millisecond)
+	for {
+		notAck := p.getNumFrameNotAck()
+		notTrans := p.getNumFramesNotTransmitted()
+		select {
+		case <-timeout:
+			if notAck != 0 && notTrans != 0 {
+				return errors.New("Timeout: " + strconv.Itoa(notAck) + "frames not ack and " + strconv.Itoa(notTrans) + " frames not transmitted")
+			} else if notAck != 0 {
+				return errors.New("Timeout: " + strconv.Itoa(notAck) + "frames not ack")
+			} else {
+				return errors.New("Timeout: " + strconv.Itoa(notTrans) + " frames not transmitted")
+			}
+
+		case <-tick:
+			if notAck == 0 && notTrans == 0 {
+				return nil
+			}
+		}
+	}
+}
+
+// Close current serial connection. Stop all threads and close all channels.
+func (p *Modem) close() (err error) {
+
+	_, file, no, ok := runtime.Caller(1)
+	if ok {
+		writeDebug("PACTOR close called from "+file+"#"+strconv.Itoa(no), 1)
+	} else {
+		writeDebug("PACTOR close called", 1)
+	}
+
+	//p.disconnect()
+	writeDebug("signal modem thread to stop", 1)
+	p.flags.stopmodem = true
+	writeDebug("waiting for all threads to exit", 1)
+	p.wg.Wait()
+	writeDebug("modem thread stopped", 1)
+
+	//p.hostmodeQuit()
+	// will not close the serial port as we reuse it
+	//p.device.Close()
+	p.stophostmode()
+	p.setState(Closed)
+	writeDebug("PACTOR close() finished", 1)
+	return nil
+}
+
+// Set specified flag (channel)
+func setFlag(flag chan struct{}) {
+	flag <- struct{}{}
+}
+
+// Get number of frames not yet transmitted by the modem
+func (p *Modem) getNumFramesNotTransmitted() int {
+	//return p.channelState.c
+	return 0
+}
+
+// Get number of frames not acknowledged by the remote station
+func (p *Modem) getNumFrameNotAck() int {
+	//return p.channelState.d
+	return 0
+}
+
+// Check if serial device is still available (e.g still connected)
+func (p *Modem) checkSerialDevice() (err error) {
+	if _, err := os.Stat(p.devicePath); os.IsNotExist(err) {
+		return fmt.Errorf("ERROR: Device %s does not exist", p.devicePath)
+	}
+	return nil
+}
+
+// Poll channel 255 with "G" command to find what channels have output.
+// Write them into the channels list.
+func (p *Modem) getChannelsWithOutput() (channels []int, err error) {
+	//Poll Channel 255 to find what channels have output
+	n, chs, err := p.writeAndGetResponse("G", 255, true, 1024)
+	if err != nil {
+		return nil, err
+	}
+
+	channels = make([]int, 0)
+
+	for i, ch := range []byte(chs)[:n-1] {
+		if (i == 0 && ch == 255) || (i == 1 && ch == 1) {
+			continue
+		}
+		channels = append(channels, int(ch)-1)
+	}
+
+	writeDebug("Channels with output: "+fmt.Sprintf("%#v", channels), 2)
+
+	return
+}
+
+// Do some checks on the returned data.
+//
+// Currently, only connection information (payload) messages are passed on
+func (p *Modem) checkResponse(resp string, ch int) (n int, data []byte, err error) {
+	if len(resp) < 3 {
+		return 0, nil, fmt.Errorf("No data")
+	}
+
+	head := []byte(resp[:3])
+	payload := []byte(resp[3:])
+	length := int(head[2]) + 1
+	pl := len(payload)
+	if int(head[0]) != ch {
+		writeDebug("WARNING: Returned data does not match polled channel\n"+hex.Dump([]byte(resp)), 1)
+		return 0, nil, fmt.Errorf("Channel missmatch")
+	}
+	if int(head[1]) == 1 { //sucess,message follows
+		writeDebug("*** SUCCESS: "+string(payload), 0)
+	}
+	if int(head[1]) == 2 {
+		writeDebug("*** ERROR: "+string(payload), 0)
+	}
+	if int(head[1]) != 7 && int(head[1]) != 3 {
+		if !s.VARAMode {
+			s.Command.Response.Enqueue(fmt.Sprintf("%s\n", payload))
+		}
+		writeDebug("Message from Modem: "+string(payload), 0)
+		return 0, nil, fmt.Errorf("Not a data response")
+	}
+	if int(head[1]) == 3 { //Link status
+		if !s.VARAMode {
+			s.Command.Response.Enqueue(fmt.Sprintf("%s\n", payload))
+		}
+		writeDebug("*** LINK STATUS: "+string(payload), 0)
+		// there is no way to get the remote callsign from the WA8DED data, so we have to parse the link status :(
+		re, err := regexp.Compile(` CONNECTED to \w{2,16}`)
+		if err != nil {
+			writeDebug("Cannot convert connect message to callsign: "+string(payload), 1)
+		} else {
+			ans := strings.ReplaceAll(string(re.Find(payload)), " CONNECTED to ", "")
+			if len(ans) > 2 { //callsign consists of 3+ characters
+				p.remoteAddr = ans
+				writeDebug("PACTOR connection to: "+ans, 0)
+				if s.VARAMode {
+					if p.state == Connecting { //outgoing connection
+						s.Command.Response.Enqueue(fmt.Sprintf("CONNECTED %s %s BW", p.localAddr, ans))
+					} else { //incoming connection
+						s.Command.Response.Enqueue(fmt.Sprintf("CONNECTED %s %s BW", ans, p.localAddr))
+					}
+				}
+				p.setState(Conntected)
+				return 0, nil, nil
+			}
+		}
+		if strings.Contains(string(payload), "DISCONNECTED") {
+			writeDebug("PACTOR DISCONNECTED", 0)
+			p.setState(Ready)
+			if s.VARAMode {
+				s.Command.Response.Enqueue("DISCONNECTED")
+			}
+			// }
+			//p.channelState.f = 0
+			return 0, nil, nil
+		}
+		return 0, nil, fmt.Errorf("Link data")
+	}
+	if length != pl {
+		writeDebug("WARNING: Data length "+strconv.Itoa(pl)+" does not match stated amount "+strconv.Itoa(length)+". After "+strconv.Itoa(p.goodChunks)+" good chunks.", 1)
+		p.goodChunks = 0
+		if pl < length {
+			// TODO: search for propper go function
+			for i := 0; i < (length - pl); i++ {
+				payload = append(payload, 0x00)
+			}
+		} else {
+			payload = payload[:length]
+		}
+	} else {
+		p.goodChunks += 1
+		writeDebug("Good chunk", 2)
+	}
+	return length, payload, nil
+}
+
+// Write and read response from pactor modem
+//
+// Can be used in both, normal and hostmode. If used in hostmode, provide
+// channel (>=0). If used in normal mode, set channel to -1, isCommand is
+// ignored.
+func (p *Modem) writeAndGetResponse(msg string, ch int, isCommand bool, chunkSize int) (int, string, error) {
+	writeDebug("wagr: Channel: "+strconv.Itoa(ch)+"; isCommand: "+strconv.FormatBool(isCommand)+"\n"+hex.Dump([]byte(msg)), 3)
+	var err error
+
+	var n int
+	var str string
+	if ch < 0 {
+		err = p._write(msg + "\r")
+		if err != nil {
+			return 0, "", err
+		}
+		time.Sleep(500 * time.Millisecond)
+		i := 0
+		var tmp []byte
+		for {
+			n, tmp, err = p._read(chunkSize)
+			str = string(tmp)
+			if err == nil {
+				break
+			}
+			i += 1
+			if i > 9 {
+				writeDebug("No successful read after 10 times!", 1)
+				return 0, "", err
+			}
+		}
+		writeDebug(fmt.Sprintf("response: %s\n%s", str, hex.Dump(tmp)), 2)
+		return n, str, err
+	} else {
+		err = p.writeChannel(msg, ch, isCommand)
+		if err != nil {
+			return 0, "", err
+		}
+		if msg == "JHOST0" { //looks like the SCS modems do not answer to JHOST0, although the standard defines it
+			return 0, "", nil
+		}
+		time.Sleep(50 * time.Millisecond)
+		writeDebug("Decode WA8DED", 4)
+		buf := []byte{}
+		valid := false
+
+		for valid == false {
+			if bytes.Compare(buf, []byte{170, 170, 170, 85}) == 0 { // check for re-request 	#170#170#170#85
+				// packet was re-requested!!
+				writeDebug("Re-Request magic received", 3)
+				buf = []byte{}                           //delete the re-request packet
+				err = p.writeChannel(msg, ch, isCommand) // write command again
+				if err != nil {
+					return 0, "", err
+				}
+			}
+			br, b, err := p._read(1)
+			if err != nil {
+				writeDebug("ERROR at _read: "+error.Error(err), 1)
+			}
+			writeDebug("Len: "+strconv.Itoa(len(buf))+"State: "+string(hex.Dump(buf)+"\n"), 4)
+			if br > 0 {
+				//we got some data
+				buf = append(buf, b...)
+				if len(buf) > 5 { // otherwise it's no enh. WA8DED: 2 magic bytes, 2 header bytes, 2 CRC bytes
+					//unstuff (from 3rd byte on)
+					t := bytes.Replace(buf[2:], []byte{170, 0}, []byte{170}, -1)
+					buf = append([]byte{0xaa, 0xaa}, t...)
+					if checkcrc(buf) {
+						n = len(t) - 2
+						str = string(t[:n])
+						valid = true
+					} else {
+						writeDebug("(still) Invalid checksum", 4)
+					}
+
+				}
+			}
+		}
+
+	}
+
+	p.packetcounter = !(p.packetcounter)
+	writeDebug("wagr: returning \n"+hex.Dump([]byte(str)), 3)
+	return n, str, err
+}
+
+// Flush waits for the last frames to be transmitted.
+//
+// Will throw error if remaining frames could not bet sent within 120s
+func (p *Modem) Flush() (err error) {
+	writeDebug("Flush called", 2)
+	if err = p.waitTransmissionFinish(120 * time.Second); err != nil {
+		writeDebug(err.Error(), 2)
+	}
+	return
+}
+
+// TxBufferLen returns the number of bytes in the out sendbuf queue.
+func (p *Modem) TxBufferLen() int {
+	writeDebug("TxBufferLen called ("+strconv.Itoa(s.Data.Data.GetLen())+" bytes remaining in sendbuf)", 2)
+	return s.Data.Data.GetLen() + (p.getNumFramesNotTransmitted() * MaxSendData)
+}
+
+func (p *Modem) Busy() bool {
+	return p.chanbusy
+}
+
+// Write to serial connection (thread safe)
+//
+// No other read/write operation allowed during this time
+func (p *Modem) write(cmd string) error {
+	p.mux.pactor.Lock()
+	defer p.mux.pactor.Unlock()
+	return p._write(cmd)
+}
+
+// Write to serial connection (NOT thread safe)
+//
+// If used, make shure to lock/unlock p.mux.pactor mutex!
+func (p *Modem) _write(cmd string) error {
+	if err := p.checkSerialDevice(); err != nil {
+		writeDebug(err.Error(), 1)
+		return err
+	}
+
+	writeDebug("write: \n"+hex.Dump([]byte(cmd)), 3)
+
+	p.mux.device.Lock()
+	defer p.mux.device.Unlock()
+	out := cmd + "\r"
+	for {
+		status, err := p.device.GetModemStatusBits()
+		if err != nil {
+			writeDebug("GetModemStatusBits failed. cmd: "+cmd+" Error: "+err.Error(), 1)
+			return err
+		}
+		if status.CTS {
+			for {
+				sent, err := p.device.Write([]byte(out))
+				if err == nil {
+					break
+				} else {
+					//					log.Errorf("ERROR while sending serial command: %s\n", out)
+					writeDebug(err.Error(), 2)
+					out = out[sent:]
+				}
+			}
+			break
+		}
+	}
+
+	return nil
+}
+
+// *** Helper functions for the CRC hostmode
+// Although these functions are small, I prefer to keep their functionality
+// separate. They follow the steps in the SCS documentation
+
+// helper function: de-hexlify and write to debug channel
+func printhex(s string) {
+	t, _ := hex.DecodeString(s)
+	writeDebug(string(t), 3)
+}
+
+// helper function: "unstuff" a string
+func unstuff(s string) string {
+	//Expect: the string contains aa aa at the beginning, that should NOT be
+	//stuffed
+	n, _ := hex.DecodeString(s[4:])
+	n = bytes.Replace(n, []byte{170, 0}, []byte{170}, -1)
+	var r []byte
+	r = append([]byte{0xaa, 0xaa}, n...)
+	re := hex.EncodeToString(r)
+	return re
+}
+
+// helper function: "stuff" a string: replaces every #170 with #170#0
+func stuff(s string) string {
+	//Expect: the string contains aa aa at the beginning, that should NOT be
+	//stuffed
+	n, err := hex.DecodeString(s[4:])
+	if err != nil {
+		writeDebug("ERROR in Stuff: "+err.Error()+"\n"+string(hex.Dump([]byte(s))), 1)
+	}
+
+	n = bytes.Replace(n, []byte{170}, []byte{170, 0}, -1)
+	var r []byte
+	r = append([]byte{0xaa, 0xaa}, n...)
+	re := hex.EncodeToString(r)
+	return re
+}
+
+// helper function: calculates the CCITT-CRC16 checksum
+func checksum(s string) uint16 {
+	tochecksum, _ := hex.DecodeString(s[4:])
+	chksum := bits.ReverseBytes16(crc16.ChecksumCCITT([]byte(tochecksum)))
+	return chksum
+}
+
+// helper fuction: check the checksum by comparing
+func checkcrc(s []byte) bool {
+	tochecksum := s[2 : len(s)-2]
+	chksum := bits.ReverseBytes16(crc16.ChecksumCCITT(tochecksum))
+	pksum := s[len(s)-2:]
+	return (binary.BigEndian.Uint16(pksum) == chksum)
+}
+
+// super helper fuction: convert an ordinary WA8DED message into a CRC-Hostmode message
+func docrc(msg string) string {
+	// step 1: add a #170170
+	msg = fmt.Sprintf("%02x%02x%s", 170, 170, msg)
+	// step 2: calculate and add the checksum
+	chksum := checksum(msg)
+	msg = fmt.Sprintf("%s%04x", msg, chksum)
+	// step 3: add "stuff" bytes
+	msg = stuff(msg)
+	return msg
+
+}
+
+// Write channel to serial connection (NOT thread safe)
+//
+// If used, make shure to lock/unlock p.mux.pactor mutex!
+func (p *Modem) writeChannel(msg string, ch int, isCommand bool) error {
+	if err := p.checkSerialDevice(); err != nil {
+		writeDebug(err.Error(), 1)
+		return err
+	}
+
+	var d byte
+	switch {
+	case !p.packetcounter && !isCommand:
+		d = byte(0x00)
+	case !p.packetcounter && isCommand:
+		d = byte(0x01)
+	case p.packetcounter && !isCommand:
+		d = byte(0x80)
+	case p.packetcounter && isCommand:
+		d = byte(0x81)
+	}
+
+	var o []byte = []byte{170, 170, byte(ch), byte(d), byte((len(msg) - 1))}
+	o = append(o, []byte(msg)...)
+	cksum := bits.ReverseBytes16(crc16.ChecksumCCITT(o[2:]))
+	cksumb := make([]byte, 2)
+	binary.BigEndian.PutUint16(cksumb, cksum)
+	o = append(o, cksumb...)
+	tostuff := o[2:]
+	tostuff = bytes.Replace(tostuff, []byte{170}, []byte{170, 0}, -1)
+	o = append([]byte{170, 170}, tostuff...)
+	/*
+		msg = fmt.Sprintf("%02x%02x%s", 170, 170, msg)
+		// step 2: calculate and add the checksum
+		chksum := checksum(msg)
+		msg = fmt.Sprintf("%s%04x", msg, chksum)
+		// step 3: add "stuff" bytes
+		msg = stuff(msg)
+	*/
+	/*c := fmt.Sprintf("%02x", ch)
+	l := fmt.Sprintf("%02x", (len(msg) - 1))
+	s := hex.EncodeToString([]byte(msg))
+	// add crc hostmode addons
+	bs, _ := hex.DecodeString(docrc(fmt.Sprintf("%s%s%s%s", c, d, l, s)))*/
+	writeDebug("write channel: \n"+hex.Dump(o), 2)
+
+	if err := p.write(string(o)); err != nil {
+		writeDebug(err.Error(), 2)
+		return err
+	}
+	/*if !isCommand {
+		p.cmdBuf <- "%Q"
+	}*/
+	return nil
+}
+
+// Read from serial connection (thread safe)
+//
+// No other read/write operation allowed during this time
+func (p *Modem) read(chunkSize int) (int, []byte, error) {
+	p.mux.pactor.Lock()
+	defer p.mux.pactor.Unlock()
+	return p._read(chunkSize)
+}
+
+// Read from serial connection (NOT thread safe)
+//
+// If used, make shure to lock/unlock p.mux.pactor mutex!
+func (p *Modem) _read(chunkSize int) (int, []byte, error) {
+	if err := p.checkSerialDevice(); err != nil {
+		writeDebug(err.Error(), 1)
+		return 0, []byte{}, err
+	}
+
+	buf := make([]byte, chunkSize)
+
+	p.mux.device.Lock()
+	defer p.mux.device.Unlock()
+	n, err := p.device.Read(buf)
+	if err != nil {
+		writeDebug("Error received during read: "+err.Error(), 1)
+		return 0, []byte{}, err
+	}
+
+	return n, buf[0:n], nil
+}
--- a/tcpserver.go
+++ b/tcpserver.go
@@ -0,0 +1,320 @@
+package main
+
+import (
+	"bufio"
+	"context"
+	"errors"
+	"fmt"
+	"github.com/TwiN/go-color"
+	"log"
+	"net"
+	"regexp"
+	"strings"
+	"time"
+)
+
+// Chunks splits a string into chunks of chunkSize length
+// by topskip taken from https://stackoverflow.com/questions/18556693/slice-string-into-letters
+func Chunks(s string, chunkSize int) []string {
+	if len(s) == 0 {
+		return nil
+	}
+	if chunkSize >= len(s) {
+		return []string{s}
+	}
+	var chunks []string = make([]string, 0, (len(s)-1)/chunkSize+1)
+	currentLen := 0
+	currentStart := 0
+	for i := range s {
+		if currentLen == chunkSize {
+			chunks = append(chunks, s[currentStart:i])
+			currentLen = 0
+			currentStart = i
+		}
+		currentLen++
+	}
+	chunks = append(chunks, s[currentStart:])
+	return chunks
+}
+
+// HandleConnection processes incoming connections
+func handleTCPCmdConnection(conn net.Conn) {
+	defer func() {
+		s.Status &^= StatusTCPCmdActive
+		conn.Close()
+	}()
+
+	s.Status |= StatusTCPCmdActive
+	// Sending "IAMLIVE" every 60 seconds
+	alivectx, alivecancel := context.WithCancel(context.Background())
+	go func(conn net.Conn, ctx context.Context) {
+		for ctx.Err() == nil {
+			if s.VARAMode {
+				s.Command.Response.Enqueue("IAMALIVE")
+			}
+			time.Sleep(60 * time.Second)
+		}
+	}(conn, alivectx)
+	defer alivecancel()
+
+	/*
+		bufferctx, buffercancel := context.WithCancel(context.Background())
+		go func(conn net.Conn, ctx context.Context) {
+			for ctx.Err() == nil {
+				if s.VARAMode {
+					s.Command.Response.Enqueue(fmt.Sprintf("BUFFER %d", s.Data.Data.GetLen()))
+				}
+				time.Sleep(10 * time.Second)
+			}
+		}(conn, bufferctx)
+		defer buffercancel()
+	*/
+
+	s.Protocol <- fmt.Sprintf(color.InGreen("TCP Cmd Connection established with %s\n"), conn.RemoteAddr())
+
+	s.Status |= StatusTCPCmdActive
+	ctx, cancel := context.WithCancel(context.Background())
+	defer cancel()
+	go func(ctx context.Context) {
+		for ctx.Err() == nil {
+			msg, err := s.Command.Response.DequeueOrWaitContext(ctx)
+			if err != nil {
+				s.Protocol <- fmt.Sprintf(color.InRed("End of Cmd Data Connection %s\n"), conn.RemoteAddr())
+				return
+			} else {
+				s.Protocol <- fmt.Sprintf(color.InCyan("Response: %s\n"), msg)
+				conn.Write([]byte(fmt.Sprintf("%s\r", msg)))
+			}
+		}
+	}(ctx)
+
+	reader := bufio.NewReader(conn)
+	for {
+		// Read incoming message
+		message, err := reader.ReadString('\r')
+		if err != nil {
+			//s.Protocol <- fmt.Sprintf(color.InRed("Connection closed by %s\n"), conn.RemoteAddr())
+			s.Status &^= StatusTCPCmdActive
+			alivecancel()
+			//buffercancel()
+			cancel()
+			conn.Close()
+			break
+		}
+
+		message = strings.TrimSpace(message)
+		re := regexp.MustCompile("[[:^ascii:]]")
+		message = re.ReplaceAllLiteralString(message, "") // prevent any non-ASCII from being sent
+
+		if message == "" { // do not send an empty message to the controller
+			continue
+		}
+		// Process the VARA TNC protocol commands
+		if s.VARAMode {
+			translatedmsg, predefanswer, err := processVARACommand(message)
+			if err != nil {
+				s.Protocol <- color.InRed(fmt.Sprintf("Error translating VARA command %s: %s\n", message, err.Error()))
+				log.Println(fmt.Sprintf("Error translating VARA command %s: %s\n", message, err.Error()))
+				s.Command.Response.Enqueue("WRONG")
+			} else {
+				if translatedmsg != "" {
+					s.Protocol <- fmt.Sprintf(color.InPurple("(V) Got: %s Sending: %s\n"), message, translatedmsg)
+					s.Command.Cmd.Enqueue(translatedmsg)
+				}
+				if predefanswer != "" {
+					s.Command.Response.Enqueue(predefanswer)
+				} else {
+					s.Command.Response.Enqueue("OK")
+				}
+			}
+		} else { // TCP Mode == passthrough
+			s.Protocol <- fmt.Sprintf(color.InPurple("(T) Sending: %s\n"), message)
+			s.Command.Cmd.Enqueue(message)
+		}
+
+	}
+}
+
+func handleTCPDataConnection(conn net.Conn) {
+	defer func() {
+		s.Status &^= StatusTCPDataActive
+		conn.Close()
+	}()
+
+	s.Protocol <- fmt.Sprintf(color.InGreen("TCP Data Connection established with %s\n"), conn.RemoteAddr())
+	s.Status |= StatusTCPDataActive
+	ctx, cancel := context.WithCancel(context.Background())
+	defer cancel()
+	go func() {
+		for {
+			msg, err := s.Data.Response.DequeueOrWaitContext(ctx, 1)
+			if err != nil {
+				s.Protocol <- fmt.Sprintf(color.InRed("End of TCP Data Connection %s\n"), conn.RemoteAddr())
+				return
+			} else {
+				//TODO: VARA
+				if !s.DaemonMode {
+					s.FromPactor.Enqueue(msg)
+				}
+				conn.Write(msg)
+			}
+		}
+	}()
+	reader := bufio.NewReader(conn)
+	for {
+		var temp []byte
+		buf := make([]byte, 1024)
+		n, err := reader.Read(buf)
+		if n > 0 {
+			temp = append(temp, buf[:n]...)
+		}
+		if err != nil {
+			s.Status &^= StatusTCPDataActive
+			cancel()
+			conn.Close()
+			return
+		}
+		//TODO: muss das nicht weg?
+		/*		if temp == 0x04 {
+					break
+				}
+		*/
+		if !s.DaemonMode {
+			s.ToPactor.Enqueue(temp)
+		}
+		if n > 255 {
+			// we can dump at max 255 bytes into
+			for _, ck := range Chunks(string(temp), 255) {
+				s.Data.Data.Enqueue([]byte(ck))
+			}
+		} else {
+			s.Data.Data.Enqueue(temp)
+		}
+	}
+}
+
+// Process VARA commands and return appropriate WA8DED command and a pre-defined answer
+func processVARACommand(command string) (string, string, error) {
+	switch {
+	case strings.HasPrefix(command, "CONNECT"):
+		re, err := regexp.MatchString(`CONNECT \w+ \w+`, command)
+		if err != nil || !re {
+			return "", "", errors.New("Error matching regex")
+		}
+		c := strings.Split(command, " ")
+		return fmt.Sprintf("C %s", c[2]), "", nil
+
+	case strings.HasPrefix(command, "DISCONNECT"):
+		return "D", "", nil
+
+	case strings.HasPrefix(command, "ABORT"):
+		return "DD", "", nil
+		//	case strings.HasPrefix(command, "VERSION"):
+		//		return "", nil
+
+	case strings.HasPrefix(command, "LISTEN"):
+		// Handle listen
+		if strings.HasSuffix(command, "ON") {
+			return "%L 1", "", nil
+		}
+		if strings.HasSuffix(command, "OFF") {
+			return "%L 0", "", nil
+		}
+		return "", "", errors.New("Neither ON nor OFF after LISTEN")
+
+	case strings.HasPrefix(command, "MYCALL"):
+		m := ""
+		// Handle MYCALL
+		s := strings.Split(command, " ")
+		if len(s) > 1 {
+			// send own callsign to PACTOR controller
+			m = s[1]
+		} else {
+			return "", "", errors.New("Invalid MYCALL command")
+		}
+		return fmt.Sprintf("%s%s", "I ", m), "", nil
+
+	case strings.HasPrefix(command, "COMPRESSION"):
+		// Handle COMPRESSION
+		return "", "", nil
+
+	case strings.HasPrefix(command, "BW"):
+		// Has no meaning for PACTOR
+		return "", "", nil
+
+	case strings.HasPrefix(command, "CHAT"):
+		// Has no meaning for PACTOR
+		return "", "", nil
+
+	case strings.HasPrefix(command, "WINLINK SESSION"):
+		// Has no meaning for PACTOR, just return "OK"
+		return "", "", nil
+
+	case strings.HasPrefix(command, "P2P SESSION"):
+		// Has no meaning for PACTOR, just return "OK"
+		return "", "", nil
+
+	case strings.HasPrefix(command, "CWID"):
+		// Has no meaning for PACTOR, just return "OK"
+		return "", "", nil
+
+	case strings.HasPrefix(command, "PUBLIC"):
+		// Has no meaning for PACTOR, just return "OK"
+		return "", "", nil
+
+	case strings.HasPrefix(command, "VERSION"):
+		return "", "VERSION 1.0.0", nil
+
+	default:
+		// Handle unrecognized commands
+		return "", "", errors.New("Unknown command")
+	}
+}
+
+func tcpCmdServer(Config *Userconfig) {
+	// Start listening for connections
+	listener, err := net.Listen("tcp", Config.ServerAddress)
+	if err != nil {
+		s.Protocol <- fmt.Sprintf(color.InWhiteOverRed("Error starting server: %v\n"), err)
+		log.Println(err)
+		return
+	}
+	defer listener.Close()
+
+	s.Protocol <- fmt.Sprintf("TCP Protocol Server listening on %s\n", Config.ServerAddress)
+
+	for {
+		// Accept incoming connection
+		conn, err := listener.Accept()
+		if err != nil {
+			s.Protocol <- fmt.Sprintf("Error accepting connection: %v\n", err)
+			continue
+		}
+
+		// Handle connection in a separate goroutine
+		go handleTCPCmdConnection(conn)
+	}
+}
+
+func tcpDataServer(Config *Userconfig) {
+	listener, err := net.Listen("tcp", Config.DataAddress)
+	if err != nil {
+		s.Protocol <- fmt.Sprintf(color.InWhiteOverRed("Error starting server: %v\n"), err)
+		log.Println(err)
+		return
+	}
+	defer listener.Close()
+
+	s.Protocol <- fmt.Sprintf("TCP Data Server listening on %s\n", Config.DataAddress)
+	for {
+		// Accept incoming connection
+		conn, err := listener.Accept()
+		if err != nil {
+			s.Protocol <- fmt.Sprintf("Error accepting connection: %v\n", err)
+			continue
+		}
+
+		// Handle connection in a separate goroutine
+		go handleTCPDataConnection(conn)
+	}
+}
--- a/tui.go
+++ b/tui.go
@@ -0,0 +1,157 @@
+package main
+
+import (
+	"fmt"
+	"github.com/TwiN/go-color"
+	"github.com/jroimartin/gocui"
+	"log"
+	"strings"
+	"time"
+	"unicode"
+)
+
+func printable(r rune) rune {
+	if r == rune('\u000d') || r == rune('\u000a') { // ctrl-r or ctrl-n
+		return rune('\u000a') //ctrl-n
+	}
+	if unicode.IsGraphic(r) {
+		return r
+	}
+	return rune('\u002e') // dot
+}
+
+func Ternary(condition bool, valueIfTrue, valueIfFalse interface{}) interface{} {
+	if condition {
+		return valueIfTrue
+	}
+	return valueIfFalse
+}
+
+func layout(g *gocui.Gui) error {
+	maxX, maxY := g.Size()
+	lwX := int(float32(maxX) * 0.8)
+
+	// "data" view: Top-left large view
+	if v, err := g.SetView("data", 0, 0, lwX-1, maxY/2-1); err != nil {
+		if err != gocui.ErrUnknownView {
+			return err
+		}
+		v.Title = "Data"
+		v.Wrap = true
+		v.Autoscroll = true
+	}
+
+	// "protocol" view: Bottom-left large view
+	if v, err := g.SetView("protocol", 0, maxY/2, lwX-1, maxY-1); err != nil {
+		if err != gocui.ErrUnknownView {
+			return err
+		}
+		v.Title = "Protocol"
+		v.Wrap = true
+		v.Autoscroll = true
+	}
+
+	// "status" view: Smaller view on the right
+	if v, err := g.SetView("status", lwX, 0, maxX-1, maxY-1); err != nil {
+		if err != gocui.ErrUnknownView {
+			return err
+		}
+		v.Title = "Status"
+	}
+
+	return nil
+}
+
+func keybindings(g *gocui.Gui) error {
+	// Quit the application with Ctrl+C
+	if err := g.SetKeybinding("", gocui.KeyCtrlC, gocui.ModNone, quit); err != nil {
+		return err
+	}
+	if err := g.SetKeybinding("", gocui.KeyCtrlT, gocui.ModNone, toggleMode); err != nil {
+		return err
+	}
+	return nil
+}
+
+func protocolUpdate(g *gocui.Gui) {
+	for {
+		msg := <-s.Protocol
+		g.Update(func(g *gocui.Gui) error {
+			v, err := g.View("protocol")
+			if err != nil {
+				log.Println(err.Error())
+				return err
+			}
+			fmt.Fprint(v, msg)
+			return nil
+		})
+	}
+}
+
+func pactorUpdate(g *gocui.Gui) {
+	for {
+		if s.ToPactor.GetLen() > 0 {
+			msg, err := s.ToPactor.Dequeue(256)
+			if err != nil {
+				log.Println(err.Error())
+				continue
+			}
+			g.Update(func(g *gocui.Gui) error {
+				v, err := g.View("data")
+				if err != nil {
+					log.Println(err.Error())
+					return err
+				}
+				fmt.Fprint(v, strings.Map(printable, string(msg)))
+				return nil
+			})
+		}
+		if s.FromPactor.GetLen() > 0 {
+			msg, err := s.FromPactor.Dequeue(256)
+			if err != nil {
+				log.Println(err.Error())
+				continue
+			}
+			g.Update(func(g *gocui.Gui) error {
+				v, err := g.View("data")
+				if err != nil {
+					log.Println(err.Error())
+					return err
+				}
+				fmt.Fprint(v, color.InRed(strings.Map(printable, string(msg))))
+				return nil
+			})
+		}
+		time.Sleep(3 * time.Second)
+	}
+}
+
+func statusUpdate(g *gocui.Gui) {
+	for {
+		time.Sleep(1 * time.Second)
+		g.Update(func(g *gocui.Gui) error {
+			v, err := g.View("status")
+			if err != nil {
+				log.Println(err.Error())
+			} else {
+				v.Clear()
+				fmt.Fprintln(v, time.Now().Format("15:04:05"))
+				fmt.Fprintln(v, Ternary(s.VARAMode, "VARA", "TCP"))
+				fmt.Fprintln(v, Ternary(s.Status&StatusTCPCmdActive != 0, color.InGreen("TCP CMD"), color.InRed("TCP CMD")))
+				fmt.Fprintln(v, Ternary(s.Status&StatusTCPDataActive != 0, color.InGreen("TCP DATA"), color.InRed("TCP DATA")))
+				fmt.Fprintln(v, fmt.Sprintf("\nCMD S: %d\nCMD R: %d\nDTA S: %d\nDTA R: %d", s.Command.Cmd.GetLen(), s.Command.Response.GetLen(), s.Data.Data.GetLen(), s.Data.Response.GetLen()))
+			}
+			return nil
+		})
+	}
+}
+
+func quit(g *gocui.Gui, v *gocui.View) error {
+	return gocui.ErrQuit
+}
+
+func toggleMode(g *gocui.Gui, v *gocui.View) error {
+	s.Protocol <- fmt.Sprintf(color.InPurple("Toggle mode\n"))
+	s.VARAMode = !s.VARAMode
+	return nil
+}