This is a new recording mode that sits alongside the much-loved realtime pattern recording; they can both be used, if desired, to create and edit the same pattern.
It’s also now possible to record pitch changes made in chromatic mode into patterns, and there are now three options for chromatic mode playback. Mono gives you standard mono playback; Legato means that changes in pitch during sample playback won’t retrigger the sample; and Poly enables samples to be played back polyphonically.
You can find out more about the SP-404 MKII update on the Roland website. It’s free for existing users.