The IBM 1621 Paper Tape Reader was used alongside the IBM 1620 Computer. The tape reader would read at a rate of 150 characters per second. This would be used to load programs into the IBM 1620.
Like with most paper tapes, the IBM 1621 tape reader uses 8-channel tape. This would typically be 6-bit character code (IBM 704 BCD character encoding was often used around this date). Even Parity was done using Track 5. Track 8 was used to indicate lower case, something that IBM 704 char set did not include, and would be ignored on systems which did not support lower case.