diff --git a/README.md b/README.md
index 5d01009..2c1c16b 100644
--- a/README.md
+++ b/README.md
@@ -5,6 +5,23 @@ Programming tool for parallel EEPROM chips, based on a ATmega16.
 Only supports AT28C256 EEPROM chips as of now.
 
 
+## Usage
+
+### Using the python tool
+
+(TODO)
+
+
+### Using the serial terminal
+
+The device uses a baud-rate of 38.4 kbps.
+Output lines end with a line feed (LF), input lines may end with LF or CR+LF.
+
+Example for using `picocom` to access the device:
+
+    picocom -b 38400 --imap lfcrlf --echo /dev/ttyUSB0
+
+
 ## Development
 
 ### VS Code configuration
diff --git a/firmware/Makefile b/firmware/Makefile
index b04be63..1020d16 100644
--- a/firmware/Makefile
+++ b/firmware/Makefile
@@ -4,7 +4,7 @@
 # Compiler and tools
 CC = avr-gcc
 OBJCOPY = avr-objcopy
-AVRDUDE = avrdude
+AVRDUDE ?= avrdude
 
 # Compiler and linker flags
 CFLAGS = -Wall -std=c11 -Os
diff --git a/firmware/src/commands.c b/firmware/src/commands.c
index 5132acb..46c01e9 100644
--- a/firmware/src/commands.c
+++ b/firmware/src/commands.c
@@ -10,12 +10,22 @@
 #include <stdlib.h>
 #include <util/delay.h>
 
+// Internal function prototypes
+void _uartPutAsciiBlock(DataBuffer buffer);
+
+// Mode: ASCII (false) or binary (true)
+bool binary_mode = false;
+
 // Execute a single parsed command
 void executeCommand(CommandLine cmdLine) {
     // Parse command
     if (strcmp(cmdLine.command, "INIT") == 0) {
         // INIT command: Initializes connection.
-        commandInit();
+        commandInit(cmdLine.arg);
+    }
+    else if (strcmp(cmdLine.command, "HELP") == 0) {
+        // HELP command: Print a list of supported commands.
+        commandHelp(cmdLine.arg);
     }
     else if (strcmp(cmdLine.command, "READ") == 0) {
         // READ command: Takes a hex address range (or single address) as argument,
@@ -40,8 +50,40 @@ void executeCommand(CommandLine cmdLine) {
     }
 }
 
-void commandInit() {
-    // TODO init... or something?
+void commandInit(char* arg) {
+    // (Re-)initialize EEPROM functions
+    eepromInit();
+
+    // Default mode: ASCII
+    binary_mode = false;
+
+    if (arg != NULL) {
+        if (strcmp(arg, "BINARY") == 0) {
+            binary_mode = true;
+        } else if (strcmp(arg, "ASCII") == 0 || strcmp(arg, "TEXT") == 0) {
+            binary_mode = false;
+        }
+    }
+
+    if (binary_mode) {
+        uartPutLine("OK (binary mode)");
+    } else {
+        uartPutLine("OK (ASCII mode)");
+    }
+}
+
+void commandHelp() {
+    uartPutLine("HELP - Supported commands:");
+    uartPutLine("HELP - HELP");
+    uartPutLine("HELP - INIT [BINARY|ASCII]");
+    uartPutLine("HELP - READ 0000:0FFF");
+    uartPutLine("HELP - WRITE 0000");
+    uartPutLine("HELP - ERASE 0000:0FFF");
+
+    // TODO remove those
+    uartPutLine("HELP - TESTREAD (only for testing)");
+    uartPutLine("HELP - TESTWRITE (only for testing)");
+
     uartPutLine("OK");
 }
 
@@ -71,22 +113,35 @@ void commandRead(char* arg) {
         // Read a single block with up to DATA_BLOCK_SIZE bytes
         range.from = eepromReadBlock(range, &buffer);
 
-        // TODO binary output
+        if (binary_mode) {
+            // Send block as binary "package":
+            // First the size of the package (1 byte) followed by the data bytes
+            uartPutChar(buffer.bytes);
 
-        // ASCII output
-        char outBuffer[20];
-        sprintf(outBuffer, "<%d>", buffer.bytes);
-        uartPutString(outBuffer);
-
-        for (int i = 0; i < buffer.bytes; i++) {
-            sprintf(outBuffer, " %02X", buffer.data[i]);
-            uartPutString(outBuffer);
+            for (int i = 0; i < buffer.bytes; i++) {
+                uartPutChar(buffer.data[i]);
+            }
+        } else {
+            // Fancy ASCII output
+            _uartPutAsciiBlock(buffer);
         }
 
-        uartPutLine(NULL);
     } while (buffer.bytes > 0);
 }
 
+void _uartPutAsciiBlock(DataBuffer buffer) {
+    char outBuffer[20];
+    sprintf(outBuffer, "<%d>", buffer.bytes);
+    uartPutString(outBuffer);
+
+    for (int i = 0; i < buffer.bytes; i++) {
+        sprintf(outBuffer, " %02X", buffer.data[i]);
+        uartPutString(outBuffer);
+    }
+
+    uartPutLine(NULL);
+}
+
 void commandWrite(char* arg) {
     if (arg == NULL) {
         uartPutLine("ERR WRITE needs a start address");
@@ -100,6 +155,12 @@ void commandWrite(char* arg) {
         return;
     }
 
+    // Only binary mode
+    if (!binary_mode) {
+        uartPutLine("ERR WRITE in ASCII mode is not implemented");
+        return;
+    }
+
     // TODO read data from input and write to EEPROM
     uartPutLine("ERR not implemented");
 }
diff --git a/firmware/src/config.h b/firmware/src/config.h
index 088d4d6..ee071d7 100644
--- a/firmware/src/config.h
+++ b/firmware/src/config.h
@@ -7,6 +7,6 @@
 #endif
 
 // Set UART Baud rate
-#define BAUD 9600UL
+#define BAUD 38400UL
 
 #endif /* CONFIG_H_ */
diff --git a/firmware/src/main.c b/firmware/src/main.c
index 056964f..cfd0404 100644
--- a/firmware/src/main.c
+++ b/firmware/src/main.c
@@ -15,7 +15,7 @@ int main(void) {
     _delay_ms(100);
 
     // Write initial message via UART
-    uartPutLine("INFO -- EEPROM programmer by binaryDiv");
+    uartPutLine("INFO - EEPROM programmer by binaryDiv");
 
     while(1) {
         // Run main loop endlessly