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.”
I took a fish head to the movies and I didn't have to pay. -- Fish Heads, Saturday Night Live, 1977.