diff --git a/m10/m1x12.c b/m10/m1x12.c
new file mode 100644
index 0000000..d71998e
--- /dev/null
+++ b/m10/m1x12.c
@@ -0,0 +1,646 @@
+
+/* big endian forest
+ *
+ * gcc -o m1x12 m1x12.c -lm
+ *
+ */
+
+
+#include <stdio.h>
+#include <stdlib.h>
+#include <string.h>
+#include <math.h>
+#ifdef WIN
+  #include <fcntl.h>  // cygwin: _setmode()
+  #include <io.h>
+#endif
+
+typedef unsigned char ui8_t;
+typedef unsigned short ui16_t;
+
+typedef struct {
+    int lat; int lon; int alt;
+    int vE; int vN; int vU;
+    double vH; double vD; double vV;
+    int date; int time;
+    char SN[12];
+} datum_t;
+
+datum_t datum;
+
+int option_verbose = 0,  // ausfuehrliche Anzeige
+    option_raw = 0,      // rohe Frames
+    option_inv = 0,      // invertiert Signal
+    option_res = 0,      // genauere Bitmessung
+    option_color = 0,
+    wavloaded = 0;
+
+
+/* -------------------------------------------------------------------------- */
+
+#define BAUD_RATE   9600 //2*4800
+
+int sample_rate = 0, bits_sample = 0, channels = 0;
+float samples_per_bit = 0;
+
+int findstr(char *buf, char *str, int pos) {
+    int i;
+    for (i = 0; i < 4; i++) {
+        if (buf[(pos+i)%4] != str[i]) break;
+    }
+    return i;
+}
+
+int read_wav_header(FILE *fp) {
+    char txt[4+1] = "\0\0\0\0";
+    unsigned char dat[4];
+    int byte, p=0;
+
+    if (fread(txt, 1, 4, fp) < 4) return -1;
+    if (strncmp(txt, "RIFF", 4)) return -1;
+    if (fread(txt, 1, 4, fp) < 4) return -1;
+    // pos_WAVE = 8L
+    if (fread(txt, 1, 4, fp) < 4) return -1;
+    if (strncmp(txt, "WAVE", 4)) return -1;
+    // pos_fmt = 12L
+    for ( ; ; ) {
+        if ( (byte=fgetc(fp)) == EOF ) return -1;
+        txt[p % 4] = byte;
+        p++; if (p==4) p=0;
+        if (findstr(txt, "fmt ", p) == 4) break;
+    }
+    if (fread(dat, 1, 4, fp) < 4) return -1;
+    if (fread(dat, 1, 2, fp) < 2) return -1;
+
+    if (fread(dat, 1, 2, fp) < 2) return -1;
+    channels = dat[0] + (dat[1] << 8);
+
+    if (fread(dat, 1, 4, fp) < 4) return -1;
+    memcpy(&sample_rate, dat, 4); //sample_rate = dat[0]|(dat[1]<<8)|(dat[2]<<16)|(dat[3]<<24);
+
+    if (fread(dat, 1, 4, fp) < 4) return -1;
+    if (fread(dat, 1, 2, fp) < 2) return -1;
+    //byte = dat[0] + (dat[1] << 8);
+
+    if (fread(dat, 1, 2, fp) < 2) return -1;
+    bits_sample = dat[0] + (dat[1] << 8);
+
+    // pos_dat = 36L + info
+    for ( ; ; ) {
+        if ( (byte=fgetc(fp)) == EOF ) return -1;
+        txt[p % 4] = byte;
+        p++; if (p==4) p=0;
+        if (findstr(txt, "data", p) == 4) break;
+    }
+    if (fread(dat, 1, 4, fp) < 4) return -1;
+
+
+    fprintf(stderr, "sample_rate: %d\n", sample_rate);
+    fprintf(stderr, "bits       : %d\n", bits_sample);
+    fprintf(stderr, "channels   : %d\n", channels);
+
+    if ((bits_sample != 8) && (bits_sample != 16)) return -1;
+
+    samples_per_bit = sample_rate/(float)BAUD_RATE;
+
+    fprintf(stderr, "samples/bit: %.2f\n", samples_per_bit);
+
+    return 0;
+}
+
+
+#define EOF_INT  0x1000000
+
+int read_signed_sample(FILE *fp) {  // int = i32_t
+    int byte, i, ret;         //  EOF -> 0x1000000
+
+    for (i = 0; i < channels; i++) {
+                           // i = 0: links bzw. mono
+        byte = fgetc(fp);
+        if (byte == EOF) return EOF_INT;
+        if (i == 0) ret = byte;
+    
+        if (bits_sample == 16) {
+            byte = fgetc(fp);
+            if (byte == EOF) return EOF_INT;
+            if (i == 0) ret +=  byte << 8;
+        }
+
+    }
+
+    if (bits_sample ==  8) return ret-128;   // 8bit: 00..FF, centerpoint 0x80=128
+    if (bits_sample == 16) return (short)ret;
+
+    return ret;
+}
+
+int par=1, par_alt=1;
+unsigned long sample_count = 0;
+
+int read_bits_fsk(FILE *fp, int *bit, int *len) {
+    static int sample;
+    int n, y0;
+    float l, x1;
+    static float x0;
+
+    n = 0;
+    do{
+        y0 = sample;
+        sample = read_signed_sample(fp);
+        if (sample == EOF_INT) return EOF;
+        sample_count++;
+        par_alt = par;
+        par =  (sample >= 0) ? 1 : -1;    // 8bit: 0..127,128..255 (-128..-1,0..127)
+        n++;
+    } while (par*par_alt > 0);
+
+    if (!option_res) l = (float)n / samples_per_bit;
+    else {                                 // genauere Bitlaengen-Messung
+        x1 = sample/(float)(sample-y0);    // hilft bei niedriger sample rate
+        l = (n+x0-x1) / samples_per_bit;   // meist mehr frames (nicht immer)
+        x0 = x1;
+    }
+
+    *len = (int)(l+0.5);
+
+    if (!option_inv) *bit = (1+par_alt)/2;  // oben 1, unten -1
+    else             *bit = (1-par_alt)/2;  // sdr#<rev1381?, invers: unten 1, oben -1
+// *bit = (1+inv*par_alt)/2; // ausser inv=0
+
+    /* Y-offset ? */
+
+    return 0;
+}
+
+/* -------------------------------------------------------------------------- */
+
+/*
+Header = Sync-Header + Sonde-Header:
+1100110011001100 1010011001001100  1101010011010011 0100110101010101 0011010011001100
+uudduudduudduudd ududduuddudduudd  uudududduududduu dudduudududududu dduududduudduudd (oder:)
+dduudduudduudduu duduudduuduudduu  ddududuudduduudd uduuddududududud uudduduudduudduu (komplement)
+ 0 0 0 0 0 0 0 0  1 1 - - - 0 0 0   0 1 1 0 0 1 0 0  1 0 0 1 1 1 1 1  0 0 1 0 0 0 0 0
+*/
+
+#define BITS 8
+#define HEADLEN 32  // HEADLEN+HEADOFS=32 <= strlen(header)
+#define HEADOFS  0
+                 // Sync-Header                     // Sonde-Header
+char header[] = "11001100110011001010011001001100"; //"011001001001111100100000"; // M10: 64 9F 20 , M2K2: 64 8F 20
+                                                    //"011101101001111100100000"; // M??: 76 9F 20
+                                                    //"011001000100100100001001"; // M10-dop: 64 49 09
+
+#define FRAME_LEN        102
+#define BITFRAME_LEN    (FRAME_LEN*BITS)
+#define RAWBITFRAME_LEN (BITFRAME_LEN*2)
+
+char buf[HEADLEN];
+int bufpos = -1;
+
+ui8_t frame_bytes[FRAME_LEN+10];
+
+#define FRAMESTART 0
+char frame_rawbits[RAWBITFRAME_LEN+8];  // frame_rawbits-32="11001100110011001010011001001100";
+char frame_bits[BITFRAME_LEN+4];
+
+
+void inc_bufpos() {
+  bufpos = (bufpos+1) % HEADLEN;
+}
+
+char cb_inv(char c) {
+    if (c == '0') return '1';
+    if (c == '1') return '0';
+    return c;
+}
+
+// Gefahr bei Manchester-Codierung: inverser Header wird leicht fehl-erkannt
+// da manchester1 und manchester2 nur um 1 bit verschoben
+int compare2() {
+    int i, j;
+
+    i = 0;
+    j = bufpos;
+    while (i < HEADLEN) {
+        if (j < 0) j = HEADLEN-1;
+        if (buf[j] != header[HEADOFS+HEADLEN-1-i]) break;
+        j--;
+        i++;
+    }
+    if (i == HEADLEN) return 1;
+
+    i = 0;
+    j = bufpos;
+    while (i < HEADLEN) {
+        if (j < 0) j = HEADLEN-1;
+        if (buf[j] != cb_inv(header[HEADOFS+HEADLEN-1-i])) break;
+        j--;
+        i++;
+    }
+    if (i == HEADLEN) return -1;
+
+    return 0;
+
+}
+
+int bits2bytes(char *bitstr, ui8_t *bytes) {
+    int i, bit, d, byteval;
+    int bitpos, bytepos;
+
+    bitpos = 0;
+    bytepos = 0;
+
+    while (bytepos < FRAME_LEN) {
+
+        byteval = 0;
+        d = 1;
+        for (i = 0; i < BITS; i++) { 
+            //bit=*(bitstr+bitpos+i); /* little endian */
+            bit=*(bitstr+bitpos+7-i);  /* big endian */
+            // bit == 'x' ?
+            if         (bit == '1')                     byteval += d;
+            else /*if ((bit == '0') || (bit == 'x'))*/  byteval += 0;
+            d <<= 1;
+        }
+        bitpos += BITS;
+        bytes[bytepos++] = byteval & 0xFF;
+        
+    }
+
+    //while (bytepos < FRAME_LEN) bytes[bytepos++] = 0;
+
+    return 0;
+}
+
+/* -------------------------------------------------------------------------- */
+// PSK  (bzw. biphase-M (oder differential Manchester?))
+// nach Synchronisation: 00,11->0 ; 01,10->1 (Phasenwechsel)
+void psk_bpm(char* frame_rawbits, char *frame_bits) {
+    int i;
+    char bit;
+    //int err = 0;
+
+    for (i = 0; i < BITFRAME_LEN; i++) {
+
+        //if (i > 0 && (frame_rawbits[2*i] == frame_rawbits[2*i-1])) err = 1;
+
+        if (frame_rawbits[2*i] == frame_rawbits[2*i+1]) bit = '0';
+        else                                            bit = '1';
+
+        //if (err) frame_bits[i] = 'x'; else
+        frame_bits[i] = bit;
+        //err = 0;
+
+    }
+}
+
+/* -------------------------------------------------------------------------- */
+
+#define OFS           (0x02)
+#define pos_GPSlat    (OFS+0x03)  // 4 byte
+#define pos_GPSlon    (OFS+0x07)  // 4 byte
+#define pos_GPSalt    (OFS+0x0B)  // 4 byte
+#define pos_GPSvE     (OFS+0x0F)  // 2 byte
+#define pos_GPSvN     (OFS+0x11)  // 2 byte
+#define pos_GPSvU     (OFS+0x13)  // 2 byte
+#define pos_GPStime   (OFS+0x15)  // 4 byte
+#define pos_GPSdate   (OFS+0x19)  // 4 byte
+
+#define pos_SN     0x5D  // 2+3 byte
+#define pos_Check  0x63  // 2 byte
+
+/* -------------------------------------------------------------------------- */
+
+
+int get_GPSpos() {
+    int i;
+    ui8_t bytes[4];
+    int val;
+
+    for (i = 0; i < 4; i++)  bytes[i] = frame_bytes[pos_GPSlat + i];
+    val = 0;
+    for (i = 0; i < 4; i++)  val |= bytes[i] << (8*(3-i));
+    datum.lat = val;
+
+    for (i = 0; i < 4; i++)  bytes[i] = frame_bytes[pos_GPSlon + i];
+    val = 0;
+    for (i = 0; i < 4; i++)  val |= bytes[i] << (8*(3-i));
+    datum.lon = val;
+
+    for (i = 0; i < 4; i++)  bytes[i] = frame_bytes[pos_GPSalt + i];
+    val = 0;
+    for (i = 0; i < 4; i++)  val |= bytes[i] << (8*(3-i));
+    datum.alt = val;
+
+    return 0;
+}
+
+int get_GPSvel() {
+    int i;
+    ui8_t bytes[2];
+    short vel16;
+    double vx, vy, vz, dir;
+
+    for (i = 0; i < 2; i++)  bytes[i] = frame_bytes[pos_GPSvE + i];
+    vel16 = bytes[0] << 8 | bytes[1];
+    datum.vE = vel16;
+    vx = vel16 / 1e2; // east
+
+    for (i = 0; i < 2; i++)  bytes[i] = frame_bytes[pos_GPSvN + i];
+    vel16 = bytes[0] << 8 | bytes[1];
+    datum.vN = vel16;
+    vy= vel16 / 1e2; // north
+
+    for (i = 0; i < 2; i++)  bytes[i] = frame_bytes[pos_GPSvU + i];
+    vel16 = bytes[0] << 8 | bytes[1];
+    datum.vU = vel16;
+    vz = vel16 / 1e2; // up
+
+    datum.vH = sqrt(vx*vx+vy*vy);
+    dir = atan2(vx, vy) * 180 / M_PI;
+    if (dir < 0) dir += 360;
+    datum.vD = dir;
+    datum.vV = vz;
+
+    return 0;
+}
+
+int get_GPStime() {
+    int i;
+    ui8_t bytes[4];
+    int val;
+
+    for (i = 0; i < 4; i++)  bytes[i] = frame_bytes[pos_GPStime + i];
+    val = 0;
+    for (i = 0; i < 4; i++)  val |= bytes[i] << (8*(3-i));
+    datum.time = val;
+
+    return 0;
+}
+
+int get_GPSdate() {
+    int i;
+    ui8_t bytes[4];
+    int val;
+
+    for (i = 0; i < 4; i++)  bytes[i] = frame_bytes[pos_GPSdate + i];
+    val = 0;
+    for (i = 0; i < 4; i++)  val |= bytes[i] << (8*(3-i));
+    datum.date = val;
+
+    return 0;
+}
+
+/* -------------------------------------------------------------------------- */
+
+int get_SN() {
+    int i;
+    unsigned byte;
+    ui8_t sn_bytes[5];
+
+    for (i = 0; i < 11; i++) datum.SN[i] = ' '; datum.SN[11] = '\0';
+
+    for (i = 0; i < 5; i++) {
+        byte = frame_bytes[pos_SN + i];
+        sn_bytes[i] = byte;
+    }
+
+    byte = sn_bytes[2];
+    sprintf(datum.SN, "%1X%02u", (byte>>4)&0xF, byte&0xF);
+    byte = sn_bytes[3] | (sn_bytes[4]<<8);
+    sprintf(datum.SN+3, " %1X %1u%04u", sn_bytes[0]&0xF, (byte>>13)&0x7, byte&0x1FFF);
+
+    return 0;
+}
+
+/* -------------------------------------------------------------------------- */
+/*
+g : F^n -> F^16      // checksum, linear
+g(m||b) = f(g(m),b)
+
+// update checksum
+f : F^16 x F^8 -> F^16 linear
+
+010100001000000101000000
+001010000100000010100000
+000101000010000001010000
+000010100001000000101000
+000001010000100000010100
+100000100000010000001010
+000000011010100000000100
+100000000101010000000010
+000000001000000000000000
+000000000100000000000000
+000000000010000000000000
+000000000001000000000000
+000000000000100000000000
+000000000000010000000000
+000000000000001000000000
+000000000000000100000000
+*/
+
+int update_checkM10(int c, ui8_t b) {
+    int c0, c1, t, t6, t7, s;
+
+    c1 = c & 0xFF;
+
+    // B
+    b  = (b >> 1) | ((b & 1) << 7);
+    b ^= (b >> 2) & 0xFF;
+
+    // A1
+    t6 = ( c     & 1) ^ ((c>>2) & 1) ^ ((c>>4) & 1);
+    t7 = ((c>>1) & 1) ^ ((c>>3) & 1) ^ ((c>>5) & 1);
+    t = (c & 0x3F) | (t6 << 6) | (t7 << 7);
+
+    // A2
+    s  = (c >> 7) & 0xFF;
+    s ^= (s >> 2) & 0xFF;
+
+
+    c0 = b ^ t ^ s;
+
+    return ((c1<<8) | c0) & 0xFFFF;
+}
+
+int checkM10(ui8_t *msg, int len) {
+    int i, cs;
+
+    cs = 0;
+    for (i = 0; i < len; i++) {
+        cs = update_checkM10(cs, msg[i]);
+    }
+
+    return cs & 0xFFFF;
+}
+
+/* -------------------------------------------------------------------------- */
+
+int print_pos() {
+    int err;
+
+    err = 0;
+    err |= get_GPSpos();
+    err |= get_GPSvel();
+    err |= get_GPStime();
+    err |= get_GPSdate();
+
+    if (!err) {
+        //fprintf(stdout, " (%06d)", datum.date);
+        fprintf(stdout, " %02d-%02d-%02d", datum.date/10000, (datum.date%10000)/100, datum.date%100);
+        //fprintf(stdout, " (%09d)", datum.time);
+        fprintf(stdout, " %02d:%02d:%06.3f ", datum.time/10000000, (datum.time%10000000)/100000, (datum.time%100000)/1000.0);
+
+        fprintf(stdout, " lat: %.6f° ", datum.lat/1e6);
+        fprintf(stdout, " lon: %.6f° ", datum.lon/1e6);
+        fprintf(stdout, " alt: %.2fm ", datum.alt/1e2);
+
+        //fprintf(stdout, "  (%.1f , %.1f , %.1f) ", datum.vE/1e2, datum.vN/1e2, datum.vU/1e2);
+        fprintf(stdout, "  vH: %.1fm/s  D: %.1f°  vV: %.1fm/s", datum.vH, datum.vD, datum.vV);
+
+        if (option_verbose /*== 2*/) {
+            get_SN();
+            printf("   SN: %s", datum.SN);
+        }
+
+    }
+    fprintf(stdout, "\n");
+
+    return err;
+}
+
+void print_frame(int pos) {
+    int i;
+    ui8_t byte;
+    int cs1, cs2;
+
+    psk_bpm(frame_rawbits, frame_bits);
+    bits2bytes(frame_bits, frame_bytes);
+
+    if (option_raw) {
+
+            for (i = 0; i < FRAME_LEN-1; i++) {
+                byte = frame_bytes[i];
+                fprintf(stdout, "%02x", byte);
+            }
+            if (option_verbose) {
+                cs1 = (frame_bytes[pos_Check] << 8) | frame_bytes[pos_Check+1];
+                cs2 = checkM10(frame_bytes, pos_Check);
+                fprintf(stdout, " # %04x", cs2);
+                if (cs1 == cs2) fprintf(stdout, " [OK]"); else fprintf(stdout, " [NO]");
+            }
+            fprintf(stdout, "\n");
+
+    }
+    else print_pos();
+
+}
+
+/* -------------------------------------------------------------------------- */
+
+
+int main(int argc, char **argv) {
+
+    FILE *fp;
+    char *fpname;
+    int i, bit, len;
+    int pos;
+    int header_found = 0;
+
+
+#ifdef WIN
+    _setmode(fileno(stdin), _O_BINARY);  // _setmode(_fileno(stdin), _O_BINARY);
+    setbuf(stdout, NULL);
+#endif
+
+    fpname = argv[0];
+    ++argv;
+    while ((*argv) && (!wavloaded)) {
+        if      ( (strcmp(*argv, "-h") == 0) || (strcmp(*argv, "--help") == 0) ) {
+            fprintf(stderr, "%s [options] audio.wav\n", fpname);
+            fprintf(stderr, "  options:\n");
+            //fprintf(stderr, "       -v, --verbose\n");
+            fprintf(stderr, "       -r, --raw\n");
+            fprintf(stderr, "       -c, --color\n");
+            //fprintf(stderr, "       -o, --offset\n");
+            return 0;
+        }
+        else if ( (strcmp(*argv, "-v") == 0) || (strcmp(*argv, "--verbose") == 0) ) {
+            option_verbose = 1;
+        }
+        else if ( (strcmp(*argv, "-vv") == 0) ) option_verbose = 2;
+        else if ( (strcmp(*argv, "-r") == 0) || (strcmp(*argv, "--raw") == 0) ) {
+            option_raw = 1;
+        }
+        else if ( (strcmp(*argv, "-i") == 0) || (strcmp(*argv, "--invert") == 0) ) {
+            option_inv = 1;  // nicht noetig
+        }
+        else if ( (strcmp(*argv, "-c") == 0) || (strcmp(*argv, "--color") == 0) ) {
+            option_color = 1;
+        }
+        else if   (strcmp(*argv, "--res") == 0) { option_res = 1; }
+        else {
+            fp = fopen(*argv, "rb");
+            if (fp == NULL) {
+                fprintf(stderr, "%s konnte nicht geoeffnet werden\n", *argv);
+                return -1;
+            }
+            wavloaded = 1;
+        }
+        ++argv;
+    }
+    if (!wavloaded) fp = stdin;
+
+
+    i = read_wav_header(fp);
+    if (i) {
+        fclose(fp);
+        return -1;
+    }
+
+
+    pos = FRAMESTART;
+
+    while (!read_bits_fsk(fp, &bit, &len)) {
+
+        if (len == 0) { // reset_frame();
+            if (pos > (pos_GPSdate+4)*2*BITS) {
+                for (i = pos; i < RAWBITFRAME_LEN; i++) frame_rawbits[i] = 0x30 + 0;
+                print_frame(pos);//byte_count
+                header_found = 0;
+                pos = FRAMESTART;
+            }
+            //inc_bufpos();
+            //buf[bufpos] = 'x';
+            continue;   // ...
+        }
+
+        for (i = 0; i < len; i++) {
+
+            inc_bufpos();
+            buf[bufpos] = 0x30 + bit;  // Ascii
+
+            if (!header_found) {
+                header_found = compare2();
+            }
+            else {
+                frame_rawbits[pos] = 0x30 + bit;  // Ascii
+                pos++;
+            
+                if (pos == RAWBITFRAME_LEN) {
+                    print_frame(pos);//FRAME_LEN
+                    header_found = 0;
+                    pos = FRAMESTART;
+                }
+            }
+
+        }
+    }
+
+    printf("\n");
+
+    fclose(fp);
+
+    return 0;
+}
+