Octratrack Midi with Sp-404 and MPC 500

Would someone mind explain how to slave the MPC500 and SP-404 to the Octatrack? Do I need a midi box of some sort?

I’ve been over the manual and I couldn’t find anything on what to do if your other components don’t have midi-thru to chain together. (The MPC lacks a midi thru and the SP-404 lacks a midi out/thru)…

Thank you!

edit; i misread your post.

If you don’t have outs or thru’s then you’ll need a MIDI splitter. I suppose for the 100 bucks you could sell the 500 and get a 1000 but I just ordered one of these.
http://www.esi-audio.com/products/m4uxt/

However, that would require the use of a computer. It doesn´t run in standalone mode AFAIK?

MidiSolutions, got several models of MIDI splitters and/or mergers for any need: http://www.midisolutions.com/products.htm

Kenton do as well: http://www.kentonuk.com/products/select/midi-utilsel.shtml