- install g77 (refer to askubuntu.com) 
 To install,first you need to download either the 32bit,or 64bit (click) g77.
 Open Terminal,and run the command(s) below:
For 32bit
tar -xzvf g77_x86_debian_and_ubuntu.tar.gz cd g77_x86_debian_and_ubuntu chmod +x ./install.sh ./install.sh
For 64bit
tar -xzvf g77_x64_debian_and_ubuntu.tar.gz cd g77_x64_debian_and_ubuntu chmod +x ./install.sh ./install.sh
run the command g77 to check
- 
install lesstif instead of motif 
 run the command:sudo apt-get install lesstif2-dev 
- 
install MDX 
 run the command(s) below:tar -xvf mdx_NTR_35238_173_73.tar 
 cd mdx_173_73
 mv Makemdx_g77 makefile
create a symbolic link for crt1.o and crti.o files
export LIBRARY_PATH=/usr/lib/x86_64-linux-gnu sudo ln /lib/x86_64-linux-gnu/libgcc_s.so.1 /usr/lib/x86_64-linux-gnu/libgcc_s.so make
run the command ./mdx to check
move the executable file mdx to $INT_BIN
- enjoy it.