Jon Anderson

at 3:14 in the video, Anderson is clearly shown playing the pedals (with his hands). It is mounted on a stand so that he can easily reach it. You can hear him playing the melody in this section on it, and it looks like he's using quite a bit of force to play it.

A user in this reddit thread confirms that this is the indeed the pedal that he is using here: https://www.reddit.com/r/yesband/comments/ekp4k8/does_anyone_know_which_keyboard_jon_anderson_is/fdd41rd/

Anderson can be seen playing the Atari Hotz Box at 4:58 in this video.

This Sound on Sound article states, "Once complete, it became his session string synth, appearing on a Who's Who of late '70s albums, including releases from artists such as Mike Oldfield, Sally Oldfield and Jon Anderson of Yes," about Ken Freeman's String Machine.

On the official Yamaha site, Jon Anderson's gear list includes a P-90 piano.

The official Yamaha site states on its Artist page for Jon Anderson that the singer uses a Clavinova CLP 995.

The official Yamaha site states on its Artist page for Anderson that he uses a Yamaha RS 7000.