Clarify EEG to FFT generation


I’m a novice trying to write my own parser but confused how the frequency bins are generated. The documentation says "[I]We use a Hamming window of 256 samples(at 220Hz), then for the next FFT we slide the window 22 samples over(1/10th of a second). This gives a 90% overlap from one window to the next.[/I]"
I understand this to mean we use an Hann window (or Hamm?) on 256 eeg values. Then perform fft on these values to get 129 frequency bins. Then slide the Hann window by adding 22 new eeg values to the original 256 while removing the first (old) 22 values from the beginning. Then repeat the fft. Is this correct?

John -