SR-16 SR-18 help will FILL operation

[big_z_in_miami]

I wish I could find a forum devoted to the Alesis SR-16/18 or any drum machine, so if you know one, please let me know.

My real question is being clear on how the FILL function works on this drum machine.

My manual led me to believe that the FILL section starts at the end of the current running section, A or B, then does it run (same length as the main section), and then switches to the other main section.

On testing, I noticed that (it sounded to me...) the FILL kicked off immediately no matter where I was in the main section, and then it switched to the next section......but the original count was maintained.

Example.....running in a 16 beat A section (verse), I hit FILL on say....the 8 beat....I hear the fill part, and it continues until the full 16 beats are completed....THEN the B section fires off.

This makes sense to me as the fill shouldn't alter the normal song structure, but just augment/alter/fill-in the last bits of the A section to transition to the B section.

Am I right with this? How long is the FILL programming then? Is a good way to build it by copying the A section to thed fill first and then modify so no matter where it is started it will remain in-time with the related section? Or if the fill is say only 4 beats long.....then it will come in at beat 12 in a 16 beat A section......so it wraps up the A section and keeps the overall structure in-time?

Looking for the most efficient way to use it and program fills.

Thanks.