The E12 sorter operated at 450 cards per minute. Cards were feed in parallel. It had only one reading station with a single movable column brush: the verification was done manually by watching the output deck in a given stacker in front of light for a common hole in the sorting column.
The D1 sorter was operating at 700 cards per minute. Its reading logic was identical to the E12.
The D3 sorter was also operating at 700 cpm but had two read stations with 80 brushes. Verification was automatic.