Came across similar situation with the following error in Python 3.8.5 [64-bit] with psychopy.__version__ == 2020.2.10 installed (via conda install psychopy):
from psychopy import parallel
p = parallel.ParallelPort('0x0378')
Solved by putting the inpoutx64.dll file in the [Windows]/System32 directory. The dll was downloaded from the following address: InpOut32 and InpOutx64
After copying the file into System32, I had to quit and restart python (or ipython) to make it work. Simply by “reset” in ipython won’t work.
Hope this helps someone with the same issue.
