diff --git a/pkgs/applications/virtualization/8086tiny/builder.sh b/pkgs/applications/virtualization/8086tiny/builder.sh
index 36c381becec..7cff2589abe 100644
--- a/pkgs/applications/virtualization/8086tiny/builder.sh
+++ b/pkgs/applications/virtualization/8086tiny/builder.sh
@@ -6,14 +6,23 @@ mkdir -p ./$name $out/bin $out/share/$name $out/share/doc/$name/images
 cd $name
 tar xf $src
 make 8086tiny
+if [ $bios ]; then
+    cd bios_source
+    nasm -f bin bios.asm -o bios
+    cd ..
+fi
 
-install 8086tiny $out/bin
-install bios $out/share/$name/8086tiny-bios
-install fd.img $out/share/$name/8086tiny-floppy.img
-install bios_source/bios.asm  $out/share/$name/8086tiny-bios-src.asmn
-install docs/8086tiny.css  $out/share/doc/$name
-install docs/doc.html  $out/share/doc/$name
+install -m 755 8086tiny $out/bin
+install -m 644 fd.img $out/share/$name/8086tiny-floppy.img
+install -m 644 bios_source/bios.asm  $out/share/$name/8086tiny-bios-src.asm
+install -m 644 docs/8086tiny.css  $out/share/doc/$name
+install -m 644 docs/doc.html  $out/share/doc/$name
 for i in docs/images/*.gif
 do
-    install $i $out/share/doc/$name/images
+    install -m 644 $i $out/share/doc/$name/images
 done
+if [ $bios ]; then
+    install -m 644 bios_source/bios $out/share/$name/8086tiny-bios
+else
+    install -m 644 bios $out/share/$name/8086tiny-bios
+fi
diff --git a/pkgs/applications/virtualization/8086tiny/default.nix b/pkgs/applications/virtualization/8086tiny/default.nix
index 8e5108b4410..a16f052f622 100644
--- a/pkgs/applications/virtualization/8086tiny/default.nix
+++ b/pkgs/applications/virtualization/8086tiny/default.nix
@@ -1,32 +1,32 @@
 { stdenv, fetchurl
-, localBios ? false, nasm ? null
+, localBios ? true, nasm ? null
 , sdlSupport ? true, SDL ? null
 }:
 
-
 assert sdlSupport -> (SDL != null);
 
-
 stdenv.mkDerivation rec {
 
   name = "8086tiny-${version}";
-  version = "1.20";
+  version = "1.25";
 
   src = fetchurl {
-    url ="http://www.megalith.co.uk/8086tiny/downloads/8086tiny_120.tar.bz2";
-    sha256 = "0yapnr8wvlx7h1q1w98yfy2vsbf0rlp4wd99r3xb0b7l70b36mpw";
+    url ="http://www.megalith.co.uk/8086tiny/downloads/8086tiny_125.tar.bz2";
+    sha256 = "0kmq4iiwhi2grjwq43ljjk1b1f1v1x9gzrgrgq2fzfsj7m7s6ris";
   };
 
   buildInputs = with stdenv.lib;
   optionals localBios [ nasm ]
   ++  optionals sdlSupport [ SDL ];
-
+  
+  bios = localBios;
+  
   builder = ./builder.sh;
 
   meta = {
     description = "An open-source 8086 emulator";
     longDescription = ''
-    8086tiny is a tiny, open source (MIT), portable (little-endian hosts) Intel PC emulator, powerful enough to run DOS, Windows 3.0, Excel, MS Flight Simulator, AutoCAD, Lotus 1-2-3, and similar applications. 8086tiny emulates a "late 80's era" PC XT-type machine.
+    8086tiny is a tiny, open-source (MIT), portable (little-endian hosts) Intel PC emulator, powerful enough to run DOS, Windows 3.0, Excel, MS Flight Simulator, AutoCAD, Lotus 1-2-3, and similar applications. 8086tiny emulates a "late 80's era" PC XT-type machine.
 
     8086tiny is based on an IOCCC 2013 winning entry. In fact that is the "unobfuscated" version :)
     '';