WarGames 8" floppies
Yes, Matthew Broderick's character David Lightman was using 8" floppies in his IMSAI 8080 drives. According to the director's commentary on the DVD I have, the whole setup - even though it was fairly ancient when the film was made - was chosen because the interactions with it, especially the use of an acoustic coupler instead of a plug-in modem, made it far more obvious what was going on than those with a newer computer would. This was also why they came up with the idea for the online interaction with WOPR to be read out by John Wood/Dr. Stephen Falken - text to speech was nowhere near that good in those days, but it significantly increased the dramatic tension.