Pion excitation functions in proton-nucleus collisions, from the absolute t
hreshold to 500 MeV, have been measured with 1 MeV beam energy resolution a
t the CELSIUS storage ring, operating in slow ramping mode. Total yields, a
ngular distributions, and target mass dependence of pi(+) production are ge
nerally reproduced well by QMD calculations. The pi(+)/pi(-) ratios are not
reproduced equally well, obviously because the detailed description of the
pion interaction with the Coulomb field is very delicate.