Roland G / BK
4 Mains
4 Intros
4 Endings
6 Fill-ins
each part can have different patterns for Maj/Min/7th chords
54 total patterns

Korg Pa
4 Mains
3 Intros
3 Endings
4 Fill-ins
1 Break
You can have 6 different patterns for main and 2 patterns for others, assignable to different chord types.
46 total patterns

Yamaha Tyros/PSR
4 Mains
3 Intro
3 Endings
4 Fill-ins
1 Break
1 pattern for each
15 total patterns