We use to call it the "washing machine". Had a ring of 'data cells', and the ring rotated back and forward like a washing machine tub.

Rotation was to bring a particular data cell to the one read head. The data cells were removeable and IIRC each was about 12-18 ins long & 3-4 ins wide & 2-3 ins deep.

Each data cell held a number of mag strips slightly smaller than the above dimesions. When at the read head, the top of the data cell was opened & some 'fingers' would grab one of the mag strips (each mag strip had a tab at the top) and as a read-load mechanism pulled the strip out the fingers would hold the other strips apart ready for dumping the mag strip back into the data cell when no longer needed.

The read-load mechanism wrapped the mag strip around a small drum frame and read/wrote it like a mag drum. When finished it would unwrap the strip from the drum while sliding it back into its correct position in the data cell. The data cell got closed then the washing machine rotated to the next cell to be accessed.

This device plus the 1419 bank-cheque sorter, were devices to behold & marvel at.