Note for others who manually install systemd service for a2pid

[xandark]

To enable:

sudo systemctl enable --system /home/USER/apple2pi/share/a2pi.service

and to start immediately:

sudo systemctl start a2pi

[oliverschmidt]

When the file are put into their intended destinations with make install, the command would rather be:

sudo systemctl enable --system /usr/local/share/a2pi/a2pi.service