het Paddy
im not shure if im getting it right..but any midi sequencer would be fine....midi as opposed to audio as very few limitations about the # of tracks it can handle...the smaleest sequencer of today is about 64 midim tracks(cubasis AV) and im pretty shure it has gone up to 128 by now ...
so anything would do...cakewalk,cubase,logic,
Studio vision(more high end)...

And if it's only midi u want to sequence...an older version of any of those would do fine...

Look around the netand you'll be able to find any of the above...(specially the older ones as they seem to be obsolete...which makes em very easy to find...)

Im also not shure if i got that one right either but are u looking for a S-612...im selling one with the disk drive...

Goo luK