Depending on the WU the FAH client will download a suitable fahcore file (.fah or .bz) from the Stanford FAH servers. You can also download these files by hand, but these are not usable as is. Under linux you have to download the .bz file and extract it. Windows and MacOSX users have to download the .fah wrapped file and convert it before extraction.
Note 1: Not every FAH core has .bz file available.
Note 2: The most common reason for downloading FahCores manually is a repeated failure of the automatic download. In many cases, the repeated failures are the result of a corrupt copy in your browser cache. Before attempting this procedure, manually empty your browser cache and allow the client to try again.
For interested parties, the .fah file structure is simple enough to easily make a wrapper from a .fah file to a .bz file - just seek to position 0x200 in the .fah file and dump the rest into a file with a .exe.bz extension. This technique is used in the instructions below.
Core download locations:
NOTE: Windows Vista users who installed a F@h client in the C:\Program Files\<fah folder> may experience a fahcore download error due to the higher default security settings in that OS. This problem is easily corrected by setting the fah executable to Run As Administrator.
Instructions for manually downloading and extracting FahCore files
Note: If both .bz and .fah files exist, download whichever is the most recent based on the timestamp.
Note: It seems that some earlier versions of Winrar do not handle .bz files as expected with regard to the naming convention of any files contained within. If this happens, extract the file, which will probably be named Core_xx (with no extension) and manually rename it to FahCore_xx.exe (xx still refers to the core number).
Extracting the latest FahCore_a0:
The procedure documented above will not work for the latest FahCore_a0, because it now delivers two files, not one. Here is the procedure how to extract it:
Third Party Tools
You can also use FoldingForum: CoreDownloader, which basically automates the process described in this wiki page.
'Shell script for Unix/Linux/Unix-like operating systems'
#!/bin/sh CORE_DOWNLOAD_PATH="http://www.stanford.edu/~pande/Linux/x86/" FAH_PLATFORM=$(echo $CORE_DOWNLOAD_PATH | cut -d\/ -f5) which curl && DLCMD="curl -s" which wget && DLCMD="wget -q -O -" if [ -z "$DLCMD" ] || [ ! "$DLCMD" ];then echo "No download client was found, please install curl or wget and ensure they are located within you path" exit 1 fi for CORE in `$DLCMD $CORE_DOWNLOAD_PATH | sed -n 's/.*href=\"\(.*\.fah\)\".*/\1/p'`;do case $CORE in Core_a0.fah) if [ $FAH_PLATFORM = "Win32" ];then echo "Downloading $CORE" $DLCMD $CORE_DOWNLOAD_PATH$CORE | tail -c +513 | bunzip2 -qdc > FahCore_a0.tmp echo "Extracting FahCore_a0.exe" head -c +1656976 FahCore_a0.tmp | tail -c +73 | sed -e 's/PAPADDINGXX.*//g' > FahCore_a0.exe echo "Extracting libfftw3f-3.dll" tail -c +1656977 FahCore_a0.tmp > libfftw3f-3.dll rm -f FahCore_a0.tmp else echo "Downloading and extracting $CORE" $DLCMD $CORE_DOWNLOAD_PATH$CORE | tail -c +513 | bunzip2 -qdc > $(echo $CORE | sed -e 's/\.fah/\.exe/g' -e 's/^/Fah/g') fi ;; FahCore_a4.exe.fah) echo "Downloading and extracting $CORE" $DLCMD $CORE_DOWNLOAD_PATH$CORE | tail -c +513 | bunzip2 -qdc > FahCore_a4.exe ;; *) echo "Downloading and extracting $CORE" $DLCMD $CORE_DOWNLOAD_PATH$CORE | tail -c +513 | bunzip2 -qdc > $(echo $CORE | sed -e 's/\.fah/\.exe/g' -e 's/^/Fah/g') ;; esac done
Substitute the CORE_DOWNLOAD_PATH variable's value with any of the above listed Core download locations.
Shell script requires a cli download program such as either curl or wget and the tail, bunzip, sed, cut commands.
Tested on Linux and should potentially work under Mac OS X, BSD and Cygwin provided the required commands are installed.
Will not work correctly download and extract FahCore_a0 as mentioned above, this feature maybe added later.