diff --git a/dfu.c b/dfu.c
index 718b991..d8d114f 100644
--- a/dfu.c
+++ b/dfu.c
@@ -30,10 +30,9 @@
 #include <string.h>
 #include <unistd.h>
 #include <libusb-1.0/libusb.h>
-#include "util.h"
 
 //
-// All DFU based Commands
+// USB request types.
 //
 #define REQUEST_TYPE_TO_HOST    0xA1
 #define REQUEST_TYPE_TO_DEVICE  0x21
@@ -242,7 +241,28 @@ static void erase_block(uint32_t address)
     wait_dfu_idle();
 }
 
-void dfu_init(unsigned vid, unsigned pid, int write_nbytes)
+static const char *identify()
+{
+    static uint8_t data[64];
+
+    md380_command(0xa2, 0x01);
+
+    int error = libusb_control_transfer(dev, REQUEST_TYPE_TO_HOST,
+        REQUEST_UPLOAD, 0, 0, data, 64, 0);
+    if (error < 0) {
+        fprintf(stderr, "%s: cannot read data: %d: %s\n",
+            __func__, error, libusb_strerror(error));
+        exit(-1);
+    }
+    //printf("%02x-%02x-%02x-%02x-%02x-%02x-%02x-%02x-%02x-%02x-%02x-%02x-%02x-%02x-%02x-%02x\n",
+    //data[0], data[1], data[2], data[3], data[4], data[5], data[6], data[7],
+    //data[8], data[9], data[10], data[11], data[12], data[13], data[14], data[15]);
+
+    get_status();
+    return (const char*) data;
+}
+
+const char *dfu_init(uint16_t vid, uint16_t pid)
 {
     int error = libusb_init(&ctx);
     if (error < 0) {
@@ -278,31 +298,13 @@ void dfu_init(unsigned vid, unsigned pid, int write_nbytes)
     // Enter Programming Mode.
     md380_command(0x91, 0x01);
 
-    if (write_nbytes > 0) {
-        erase_block(0x00000000);
-        erase_block(0x00010000);
-        erase_block(0x00020000);
-        erase_block(0x00030000);
-
-        if (write_nbytes > 256*1024) {
-            erase_block(0x00110000);
-            erase_block(0x00120000);
-            erase_block(0x00130000);
-            erase_block(0x00140000);
-            erase_block(0x00150000);
-            erase_block(0x00160000);
-            erase_block(0x00170000);
-            erase_block(0x00180000);
-            erase_block(0x00190000);
-            erase_block(0x001a0000);
-            erase_block(0x001b0000);
-            erase_block(0x001c0000);
-            erase_block(0x001d0000);
-        }
-    }
+    // Get device identifier in a static buffer.
+    const char *ident = identify();
 
     // Zero address.
     set_address(0x00000000);
+
+    return ident;
 }
 
 void dfu_close()
@@ -315,7 +317,31 @@ void dfu_close()
     }
 }
 
-void dfu_read_block(int bno, unsigned char *data, int nbytes)
+void dfu_erase(int nbytes)
+{
+    erase_block(0x00000000);
+    erase_block(0x00010000);
+    erase_block(0x00020000);
+    erase_block(0x00030000);
+
+    if (nbytes > 256*1024) {
+        erase_block(0x00110000);
+        erase_block(0x00120000);
+        erase_block(0x00130000);
+        erase_block(0x00140000);
+        erase_block(0x00150000);
+        erase_block(0x00160000);
+        erase_block(0x00170000);
+        erase_block(0x00180000);
+        erase_block(0x00190000);
+        erase_block(0x001a0000);
+        erase_block(0x001b0000);
+        erase_block(0x001c0000);
+        erase_block(0x001d0000);
+    }
+}
+
+void dfu_read_block(int bno, uint8_t *data, int nbytes)
 {
     if (bno >= 256)
         bno += 832;
@@ -331,7 +357,7 @@ void dfu_read_block(int bno, unsigned char *data, int nbytes)
     get_status();
 }
 
-void dfu_write_block(int bno, unsigned char *data, int nbytes)
+void dfu_write_block(int bno, uint8_t *data, int nbytes)
 {
     if (bno >= 256)
         bno += 832;
@@ -346,39 +372,3 @@ void dfu_write_block(int bno, unsigned char *data, int nbytes)
 
     get_status();
 }
-
-#if 0
-void device_to_file(const char *filename)
-{
-    FILE *out = fopen(filename, "w");
-    if (! out) {
-        perror(filename);
-        exit(-1);
-    }
-
-    int bno;
-    for (bno=0; bno<832; bno++) {
-        uint8_t data[1024];
-        dfu_read_block(bno, data, 1024);
-
-        if (fwrite(data, 1, 1024, out) != 1024) {
-            printf("\n");
-            fprintf(stderr, "%s: cannot write output image!\n", __func__);
-            exit(-1);
-        }
-        printf(".");
-        fflush(stdout);
-    }
-    printf("\n");
-    fclose(out);
-}
-
-int main()
-{
-    dfu_init(0x0483, 0xdf11, 0);
-
-    device_to_file("output.img");
-
-    dfu_close();
-}
-#endif
diff --git a/main.c b/main.c
index c606f95..a48f863 100644
--- a/main.c
+++ b/main.c
@@ -61,7 +61,7 @@ void usage()
 
 int main(int argc, char **argv)
 {
-    int write_flag = 0, config_flag = 0;
+    int read_flag = 0, write_flag = 0, config_flag = 0;
 
     // Set locale and message catalogs.
     setlocale(LC_ALL, "");
@@ -77,8 +77,9 @@ int main(int argc, char **argv)
     copyright = _("Copyright (C) 2018 Serge Vakulenko KK6ABQ");
     serial_verbose = 0;
     for (;;) {
-        switch (getopt(argc, argv, "vcw")) {
+        switch (getopt(argc, argv, "vcwr")) {
         case 'v': ++serial_verbose; continue;
+        case 'r': ++read_flag;      continue;
         case 'w': ++write_flag;     continue;
         case 'c': ++config_flag;    continue;
         default:
@@ -99,20 +100,20 @@ int main(int argc, char **argv)
 
     if (write_flag) {
         // Restore image file to device.
-        if (argc != 2)
+        if (argc != 1)
             usage();
 
         radio_connect();
-        radio_read_image(argv[1]);
+        radio_read_image(argv[0]);
         radio_print_version(stdout);
         radio_upload(0);
         radio_disconnect();
 
     } else if (config_flag) {
-        if (argc != 2)
+        if (argc != 1 && argc != 2)
             usage();
 
-        if (is_file(argv[0])) {
+        if (argc == 2) {
             // Apply text config to image file.
             radio_read_image(argv[0]);
             radio_print_version(stdout);
@@ -125,16 +126,16 @@ int main(int argc, char **argv)
             radio_download();
             radio_print_version(stdout);
             radio_save_image("backup.img");
-            radio_parse_config(argv[1]);
+            radio_parse_config(argv[0]);
             radio_upload(1);
             radio_disconnect();
         }
 
-    } else {
-        if (argc != 1)
+    } else if (read_flag) {
+        if (argc != 0 && argc != 1)
             usage();
 
-        if (is_file(argv[0])) {
+        if (argc == 1) {
             // Print configuration from image file.
             // Load image from file.
             radio_read_image(argv[0]);
@@ -161,6 +162,8 @@ int main(int argc, char **argv)
             radio_print_config(conf, 1);
             fclose(conf);
         }
+    } else {
+        usage();
     }
     return 0;
 }
diff --git a/md380.c b/md380.c
index c603d2b..b635bb2 100644
--- a/md380.c
+++ b/md380.c
@@ -299,108 +299,22 @@ static void md380_print_version(FILE *out)
     // Nothing to print.
 }
 
-//
-// Read block of data, up to 64 bytes.
-// When start==0, return non-zero on success or 0 when empty.
-// When start!=0, halt the program on any error.
-//
-static int read_block(int fd, int start, unsigned char *data, int nbytes)
-{
-    unsigned char reply;
-    int len;
-
-    // Read data.
-    len = serial_read(fd, data, nbytes);
-    if (len != nbytes) {
-        if (start == 0)
-            return 0;
-        fprintf(stderr, "Reading block 0x%04x: got only %d bytes.\n", start, len);
-        exit(-1);
-    }
-
-    // Get acknowledge.
-    serial_write(fd, "\x06", 1);
-    if (serial_read(fd, &reply, 1) != 1) {
-        fprintf(stderr, "No acknowledge after block 0x%04x.\n", start);
-        exit(-1);
-    }
-    if (reply != 0x06) {
-        fprintf(stderr, "Bad acknowledge after block 0x%04x: %02x\n", start, reply);
-        exit(-1);
-    }
-    if (serial_verbose) {
-        printf("# Read 0x%04x: ", start);
-        print_hex(data, nbytes);
-        printf("\n");
-    } else {
-        ++radio_progress;
-        if (radio_progress % 16 == 0) {
-            fprintf(stderr, "#");
-            fflush(stderr);
-        }
-    }
-    return 1;
-}
-
-//
-// Write block of data, up to 64 bytes.
-// Halt the program on any error.
-// Return 0 on error.
-//
-static int write_block(int fd, int start, const unsigned char *data, int nbytes)
-{
-    unsigned char reply[64];
-    int len;
-
-    serial_write(fd, data, nbytes);
-
-    // Get echo.
-    len = serial_read(fd, reply, nbytes);
-    if (len != nbytes) {
-        fprintf(stderr, "! Echo for block 0x%04x: got only %d bytes.\n", start, len);
-        return 0;
-    }
-
-    // Get acknowledge.
-    if (serial_read(fd, reply, 1) != 1) {
-        fprintf(stderr, "! No acknowledge after block 0x%04x.\n", start);
-        return 0;
-    }
-    if (reply[0] != 0x06) {
-        fprintf(stderr, "! Bad acknowledge after block 0x%04x: %02x\n", start, reply[0]);
-        return 0;
-    }
-    if (serial_verbose) {
-        printf("# Write 0x%04x: ", start);
-        print_hex(data, nbytes);
-        printf("\n");
-    } else {
-        ++radio_progress;
-        if (radio_progress % 16 == 0) {
-            fprintf(stderr, "#");
-            fflush(stderr);
-        }
-    }
-    return 1;
-}
-
 //
 // Read memory image from the device.
 //
 static void md380_download()
 {
-    int addr;
+    int bno;
 
-    // Wait for the first 8 bytes.
-    while (read_block(radio_port, 0, &radio_mem[0], 8) == 0)
-        continue;
+    for (bno=0; bno<MEMSZ/1024; bno++) {
+        dfu_read_block(bno, &radio_mem[bno*1024], 1024);
 
-    // Get the rest of data.
-    for (addr=8; addr<MEMSZ; addr+=64)
-        read_block(radio_port, addr, &radio_mem[addr], 64);
-
-    // Get the checksum.
-    read_block(radio_port, MEMSZ, &radio_mem[MEMSZ], 1);
+        ++radio_progress;
+        if (radio_progress % 16 == 0) {
+            fprintf(stderr, "#");
+            fflush(stderr);
+        }
+    }
 }
 
 //
@@ -408,20 +322,19 @@ static void md380_download()
 //
 static void md380_upload(int cont_flag)
 {
-    int addr;
-    char buf[80];
+    int bno;
+
+    dfu_erase(MEMSZ);
 
-    if (! fgets(buf, sizeof(buf), stdin))
-	/*ignore*/;
     fprintf(stderr, "Sending data... ");
     fflush(stderr);
+    for (bno=0; bno<MEMSZ/1024; bno++) {
+        dfu_write_block(bno, &radio_mem[bno*1024], 1024);
 
-    if (! write_block(radio_port, 0, &radio_mem[0], 8)) {
-        //TODO
-    }
-    for (addr=8; addr<MEMSZ; addr+=64) {
-        if (! write_block(radio_port, addr, &radio_mem[addr], 64)) {
-            //TODO
+        ++radio_progress;
+        if (radio_progress % 16 == 0) {
+            fprintf(stderr, "#");
+            fflush(stderr);
         }
     }
 }
@@ -1112,7 +1025,7 @@ static void md380_read_image(FILE *img)
 //
 static void md380_save_image(FILE *img)
 {
-    fwrite(&radio_mem[0], 1, MEMSZ+1, img);
+    fwrite(&radio_mem[0], 1, MEMSZ, img);
 }
 
 //
diff --git a/radio.c b/radio.c
index 715aa70..919c9d2 100644
--- a/radio.c
+++ b/radio.c
@@ -35,7 +35,6 @@
 #include "radio.h"
 #include "util.h"
 
-int radio_port;                         // File descriptor of programming serial port
 unsigned char radio_mem [1024*1024];    // Radio memory contents, up to 1Mbyte
 int radio_progress;                     // Read/write progress counter
 
@@ -49,7 +48,7 @@ void radio_disconnect()
     fprintf(stderr, "Close device.\n");
 
     // Restore the port mode.
-    serial_close(radio_port);
+    dfu_close();
 
     // Radio needs a timeout to reset to a normal state.
     mdelay(2000);
@@ -68,9 +67,20 @@ void radio_print_version(FILE *out)
 //
 void radio_connect()
 {
-    //fprintf(stderr, "Connect to %s.\n", port_name);
-    //radio_port = serial_open(port_name);
-    //TODO
+    // Only TYT MD family for now.
+    const char *ident = dfu_init(0x0483, 0xdf11);
+    fprintf(stderr, "Connect to %s.\n", ident);
+
+    if (strcasecmp(ident, "MD380") == 0) {
+        device = &radio_md380;
+    } else
+    if (strcasecmp(ident, "MD-UV380") == 0) {
+        device = &radio_uv380;
+    } else {
+        fprintf(stderr, "Unrecognized radio '%s'.\n",
+            ident);
+        exit(-1);
+    }
 }
 
 //
diff --git a/util.c b/util.c
index f334e41..bfb0cb9 100644
--- a/util.c
+++ b/util.c
@@ -68,43 +68,6 @@ void print_hex(const unsigned char *data, int len)
         printf("-%02x", (unsigned char) data[i]);
 }
 
-//
-// Open the serial port.
-//
-int serial_open()
-{
-    //TODO
-    return 0;
-}
-
-//
-// Close the serial port.
-//
-void serial_close(int fd)
-{
-    // Restore the port mode.
-    //TODO
-}
-
-//
-// Read data from serial port.
-// Return 0 when no data available.
-// Use 200-msec timeout.
-//
-int serial_read(int fd, unsigned char *data, int len)
-{
-    //TODO
-    return 0;
-}
-
-//
-// Write data to serial port.
-//
-void serial_write(int fd, const void *data, int len)
-{
-    //TODO
-}
-
 //
 // Delay in milliseconds.
 //
diff --git a/util.h b/util.h
index 08bd8a1..89e625d 100644
--- a/util.h
+++ b/util.h
@@ -55,33 +55,12 @@ int serial_verbose;
 //
 void print_hex(const unsigned char *data, int len);
 
-//
-// Open the serial port.
-//
-int serial_open(void);
-
-//
-// Close the serial port.
-//
-void serial_close(int fd);
-
-//
-// Read data from serial port.
-// Return 0 when no data available.
-// Use 200-msec timeout.
-//
-int serial_read(int fd, unsigned char *data, int len);
-
-//
-// Write data to serial port.
-//
-void serial_write(int fd, const void *data, int len);
-
 //
 // DFU functions.
 //
-void dfu_init(unsigned vid, unsigned pid, int write_nbytes);
+const char *dfu_init(unsigned vid, unsigned pid);
 void dfu_close(void);
+void dfu_erase(int nbytes);
 void dfu_read_block(int bno, unsigned char *data, int nbytes);
 void dfu_write_block(int bno, unsigned char *data, int nbytes);
 
diff --git a/uv380.c b/uv380.c
index 2f43047..ea8f894 100644
--- a/uv380.c
+++ b/uv380.c
@@ -323,108 +323,22 @@ static void uv380_print_version(FILE *out)
     // Nothing to print.
 }
 
-//
-// Read block of data, up to 64 bytes.
-// When start==0, return non-zero on success or 0 when empty.
-// When start!=0, halt the program on any error.
-//
-static int read_block(int fd, int start, unsigned char *data, int nbytes)
-{
-    unsigned char reply;
-    int len;
-
-    // Read data.
-    len = serial_read(fd, data, nbytes);
-    if (len != nbytes) {
-        if (start == 0)
-            return 0;
-        fprintf(stderr, "Reading block 0x%04x: got only %d bytes.\n", start, len);
-        exit(-1);
-    }
-
-    // Get acknowledge.
-    serial_write(fd, "\x06", 1);
-    if (serial_read(fd, &reply, 1) != 1) {
-        fprintf(stderr, "No acknowledge after block 0x%04x.\n", start);
-        exit(-1);
-    }
-    if (reply != 0x06) {
-        fprintf(stderr, "Bad acknowledge after block 0x%04x: %02x\n", start, reply);
-        exit(-1);
-    }
-    if (serial_verbose) {
-        printf("# Read 0x%04x: ", start);
-        print_hex(data, nbytes);
-        printf("\n");
-    } else {
-        ++radio_progress;
-        if (radio_progress % 16 == 0) {
-            fprintf(stderr, "#");
-            fflush(stderr);
-        }
-    }
-    return 1;
-}
-
-//
-// Write block of data, up to 64 bytes.
-// Halt the program on any error.
-// Return 0 on error.
-//
-static int write_block(int fd, int start, const unsigned char *data, int nbytes)
-{
-    unsigned char reply[64];
-    int len;
-
-    serial_write(fd, data, nbytes);
-
-    // Get echo.
-    len = serial_read(fd, reply, nbytes);
-    if (len != nbytes) {
-        fprintf(stderr, "! Echo for block 0x%04x: got only %d bytes.\n", start, len);
-        return 0;
-    }
-
-    // Get acknowledge.
-    if (serial_read(fd, reply, 1) != 1) {
-        fprintf(stderr, "! No acknowledge after block 0x%04x.\n", start);
-        return 0;
-    }
-    if (reply[0] != 0x06) {
-        fprintf(stderr, "! Bad acknowledge after block 0x%04x: %02x\n", start, reply[0]);
-        return 0;
-    }
-    if (serial_verbose) {
-        printf("# Write 0x%04x: ", start);
-        print_hex(data, nbytes);
-        printf("\n");
-    } else {
-        ++radio_progress;
-        if (radio_progress % 16 == 0) {
-            fprintf(stderr, "#");
-            fflush(stderr);
-        }
-    }
-    return 1;
-}
-
 //
 // Read memory image from the device.
 //
 static void uv380_download()
 {
-    int addr;
+    int bno;
 
-    // Wait for the first 8 bytes.
-    while (read_block(radio_port, 0, &radio_mem[0], 8) == 0)
-        continue;
+    for (bno=0; bno<MEMSZ/1024; bno++) {
+        dfu_read_block(bno, &radio_mem[bno*1024], 1024);
 
-    // Get the rest of data.
-    for (addr=8; addr<MEMSZ; addr+=64)
-        read_block(radio_port, addr, &radio_mem[addr], 64);
-
-    // Get the checksum.
-    read_block(radio_port, MEMSZ, &radio_mem[MEMSZ], 1);
+        ++radio_progress;
+        if (radio_progress % 16 == 0) {
+            fprintf(stderr, "#");
+            fflush(stderr);
+        }
+    }
 }
 
 //
@@ -432,20 +346,19 @@ static void uv380_download()
 //
 static void uv380_upload(int cont_flag)
 {
-    int addr;
-    char buf[80];
+    int bno;
+
+    dfu_erase(MEMSZ);
 
-    if (! fgets(buf, sizeof(buf), stdin))
-	/*ignore*/;
     fprintf(stderr, "Sending data... ");
     fflush(stderr);
+    for (bno=0; bno<MEMSZ/1024; bno++) {
+        dfu_write_block(bno, &radio_mem[bno*1024], 1024);
 
-    if (! write_block(radio_port, 0, &radio_mem[0], 8)) {
-        //TODO
-    }
-    for (addr=8; addr<MEMSZ; addr+=64) {
-        if (! write_block(radio_port, addr, &radio_mem[addr], 64)) {
-            //TODO
+        ++radio_progress;
+        if (radio_progress % 16 == 0) {
+            fprintf(stderr, "#");
+            fflush(stderr);
         }
     }
 }
@@ -1158,7 +1071,7 @@ static void uv380_read_image(FILE *img)
 //
 static void uv380_save_image(FILE *img)
 {
-    fwrite(&radio_mem[0], 1, MEMSZ+1, img);
+    fwrite(&radio_mem[0], 1, MEMSZ, img);
 }
 
 //