According to another story from Jimmy Adkisson, a Shugart engineer, “Jim Adkisson and Don Massaro were discussing the proposed drive's size with Wang. The trio just happened to be doing their discussing at a bar. An Wang motioned to a drink napkin and stated 'about that size' which happened to be 5 1/4-inches wide.”
Esther Schindler writes: "Ready for a nostalgic trip into the wayback? We had floppy disks long before we had CDs, DVDs, or USB thumb-drives. Here’s the evolution of the portable media that changed everything about personal computing.