If Ed 5.0.4 refers to an educational software platform:
When dealing with vintage software like Ed 5.0.4, several issues commonly arise:
tar -xzvf ed-5.0.4.tar.gz
make
Some older package managers still cache version 5.0.4. For example, on a very old Debian or Ubuntu system: Ed 5.0.4 Download
sudo apt-get install ed=5.0.4-1
Note: Modern repositories have since updated to newer versions. This method will likely fail on current OS releases unless you manually point to an old snapshot repository.
cd ed-5.0.4