diff --git a/.gitignore b/.gitignore
index 644e726..c40b70c 100644
--- a/.gitignore
+++ b/.gitignore
@@ -20,6 +20,7 @@
 # ignore directories
 Debug
 
+host
 *.lst
 *.elf
 *.map
diff --git a/build.sh b/build.sh
index 0291436..6c63593 100644
--- a/build.sh
+++ b/build.sh
@@ -1,5 +1,10 @@
 #!/bin/bash
 
+# create simple text file named 'host' in this folder with IP address of your MiSTer.
+
+HOST=192.168.1.75
+[ -f host ] && HOST=$(cat host)
+
 # make script fail if any command failed,
 # so we don't need to check the exit status of every command.
 set -e
@@ -7,14 +12,14 @@ set -o pipefail
 make
 
 set +e
-plink root@192.168.1.75 -pw 1 'killall MiSTer'
+plink root@$HOST -pw 1 'killall MiSTer'
 
 set -e
 ftp -n <<EOF
-open 192.168.1.75
+open $HOST
 user root 1
 binary
 put MiSTer /media/fat/MiSTer
 EOF
 
-plink root@192.168.1.75 -pw 1 'sync;PATH=/media/fat:$PATH;MiSTer >/dev/ttyS0 2>/dev/ttyS0 </dev/null &'
+plink root@$HOST -pw 1 'sync;PATH=/media/fat:$PATH;MiSTer >/dev/ttyS0 2>/dev/ttyS0 </dev/null &'