diff --git a/README.md b/README.md
index d38cdf8..b297282 100644
--- a/README.md
+++ b/README.md
@@ -61,7 +61,24 @@ cd /pcsx-redux/src/mips/my-project
   Set it in pcsx-redux ; `Configuration > Emulation`, then reboot the emulator ; `File > Reboot`. 
   
   4. Install the [blender extension](https://github.com/ABelliqueux/blender_io_export_psx_mesh) to create your own levels.
-  
+
+# Trying on real HW
+
+If you have a real PSX, a cart flashed with [Unirom](https://github.com/JonathanDotCel/unirom8_bootdisc_and_firmware_for_ps1) and a [Serial/USB cable](https://unirom.github.io/serial_psx_cable/), you can upload the demo to the PSX memory with [NOTpsxserial](https://github.com/JonathanDotCel/NOTPSXSerial).  
+
+The engine can use [overlays](https://github.com/JaberwockySeamonstah/PSXOverlayExample/) to load data in the psx memory, so as opposed to a 'classic' project where you can just load the psx-exe in ram, we first have to load the data to a specific address, then load the exe.  
+
+First, comment out line 28 in `main.c`, so that the PSX won't look for the data on a CD :
+```c
+// #define USECD
+```
+The address we have to load the data to is defined by the 'load_all_overlays_here' symbol in `main.map`.  
+The provided `ovly_upload_helper.sh` script takes care of finding that address depending on the ps-exe name.  
+Thus, to load `Overlay.lvl1` and `main.ps-exe` in the psx ram, use :  
+```bash
+./ovly_upload_helper.sh Overlay.lvl1 main.ps-exe /dev/ttyUSB0
+```
+
 # Credits
 
 PSX code based on [example](http://psx.arthus.net/code/primdraw.7z) by [Lameguy64](https://github.com/Lameguy64)  
diff --git a/ovly-upload-helper.sh b/ovly-upload-helper.sh
index 43cc529..30d161d 100755
--- a/ovly-upload-helper.sh
+++ b/ovly-upload-helper.sh
@@ -1,4 +1,8 @@
 #!/bin/bash
+
+# Path to nops executable
+NOPS="nops"
+
 if [ $# -eq 0 ]
   then
     echo "PSX Overlay Upload helper script
@@ -8,22 +12,20 @@ Upload a binary and the corresponding executable to a real PSX memory, via uniro
 This script is dependant on NOTpsxserial being available on your system : https://github.com/JonathanDotCel/NOTPSXSerial
 Edit the $NOPS value to reflect the executable path on your system, e.g : 
     \$NOPS = '/blah/nops'
-Usage : ./ovly_upload_helper.sh bin_load_adress bin_filename psx_exe_name com_port
+Usage : ./ovly_upload_helper.sh bin_filename psx_exe_name com_port
     
-    - bin_load_adress, eg : 0x80010000 (This should correspond to the 'load_all_overlays_here' adress in your .map file. )
     - bin_filename , eg : Overlay.lvl0
     - psx_exe_name, e.g : main.ps-exe
     - com_port, e.g : /dev/ttyUSB0, COM1
 "
 else
-# Path to nops executable
-NOPS="nops"
-# $1 = bin loading address ( see .map's "load_all_overlays_here" address )
-# $2 = bin file
-# $3 = ps-exe file
-# $4 = comport 
-$NOPS /debug $4
-$NOPS /fast /bin $1 $2 $4
-$NOPS /fast /exe $3 $4
-$NOPS /slow $4
+# Find map file corresponding to ps-exe
+MAP_FILE="`echo $2 | awk -F. '{print $1}'`.map"
+# Find loading address
+LOAD_ADDR="0x`cat $MAP_FILE | grep load_all_overlays_here | awk '{print $1}' | cut -c 11-`"
+
+$NOPS /debug $3
+$NOPS /fast /bin $LOAD_ADDR $1 $3
+$NOPS /fast /exe $2 $3
+$NOPS /slow $3
 fi