diff --git a/assembly/bios/main.asm b/assembly/bios/main.asm
index f47fcf0..8d9ff75 100644
--- a/assembly/bios/main.asm
+++ b/assembly/bios/main.asm
@@ -48,6 +48,7 @@ SYSINIT_GREETING:
 ;include 'driver_hd44780.asm'
 ;include 'driver_keyboard.asm'
 include 'driver_arduino_terminal.asm'
+include 'monitor.asm'
 
 ; SYSTEM CALLS
 ; User I/O
diff --git a/assembly/bios/monitor.asm b/assembly/bios/monitor.asm
index ccfeedd..b366dc9 100644
--- a/assembly/bios/monitor.asm
+++ b/assembly/bios/monitor.asm
@@ -2,25 +2,75 @@
 ; @author Daniele Verducci
 ;
 ; Monitor commands (CMD $arg):
-;   DMP $pos Dumps first 100 bytes of memory starting at $pos
-;   SET $pos $val Replaces byte at $pos with $val
-;   LOA $pos $val Loads all the incoming bytes in memory starting from $pos
-;   RUN $pos Starts executing code from $pos
+;   H (HELP) Shows available commands
+;   D (DUMP) $pos Dumps first 100 bytes of memory starting at $pos
+;   S (SET) $pos $val Replaces byte at $pos with $val
+;   L (LOAD) $pos $val Loads all the incoming bytes in memory starting from $pos
+;   R (RUN) $pos Starts executing code from $pos
+; The commands are entered with a single letter and the program completes the command
 
 ; CONSTANTS
 ; All monitor commands are 3 chars long.
-MON_COMMAND_DMP: DB "DMP",0  ; null terminated strings
-MON_COMMAND_DMP: DB "SET",0
-MON_COMMAND_DMP: DB "LOA",0
-MON_COMMAND_DMP: DB "RUN",0
+MON_WELCOME: DB "PAT80 MEmory MOnitor 0.1"
+MON_COMMAND_HELP: DB "HELP",0  ; null terminated strings
+MON_COMMAND_DUMP: DB "DUMP",0  ; null terminated strings
+MON_COMMAND_SET: DB "SET",0
+MON_COMMAND_LOAD: DB "LOAD",0
+MON_COMMAND_RUN: DB "RUN",0
+MON_ARG_HEX: DB "0x",0
+MON_HELP: DB "Available commands: HELP, DUMP, SET, LOAD, RUN"
 
 Monitor_main:
-    ; Read from command line
-    
+    ; Print welcome string
+    ld bc, MON_WELCOME
+    call Print
+    monitor_main_loop:
+        ; Draw prompt char
+        ld a, 62 ; >
+        call Printc
+        ; Read char from command line
+        call Readc:     ; blocking: returns when a character was read and placed in A reg
+        ; Switch case
+        cp (MON_COMMAND_HELP)  ; check incoming char is equal to command's first char
+        jp z, monitor_help
+        cp (MON_COMMAND_DUMP)
+        jp z, monitor_dump
+        cp (MON_COMMAND_SET)
+        jp z, monitor_set
+        cp (MON_COMMAND_LOAD)
+        jp z, monitor_load
+        cp (MON_COMMAND_RUN)
+        jp z, monitor_run
+    jp monitor_main_loop
+
+monitor_help:
+    ld bc, MON_COMMAND_HELP + 1 ; autocomplete command
+    call Print
+
+    ld bc, MON_HELP
+    call Print
     ret
 
-; Parses a command
-; TODO: This is not very efficient, should be implemented as a tree, but for few commands is ok...
-; return A The interpreted command, or 0 if not found
-monitor_parse:
+monitor_dump:
+    ld bc, MON_COMMAND_DUMP + 1 ; autocomplete command
+    call Print
     ret
+
+monitor_set:
+    ld bc, MON_COMMAND_SET + 1 ; autocomplete command
+    call Print
+    ret
+
+monitor_load:
+    ld bc, MON_COMMAND_LOAD + 1 ; autocomplete command
+    call Print
+    ret
+
+monitor_run:
+    ld bc, MON_COMMAND_RUN + 1 ; autocomplete command
+    call Print
+    jp APP_VAR_SPACE    ; Start executing code
+    ret
+
+
+