Thanks again, this is looking hopeful. That software looks a bit daunting for a MIDI novice, but have now used it to upgrade my Beatstep's firmware for start. :-) I'll take it one step at a time and get help along the way.
(EDIT): Note for myself & anyone else who's interested:
Roland SP404sx manual page 48 - MIDI Implementation Chart:
Recognized: * Basic channel 1 - 16
* Mode (Default) Mode 3
* Note Number 46 - 106
* Velocity
* System Common - Song Position
* System Clock
* Real Time Commands
* Aux Messages: All Sound Off & Active Sensing
UPDATE: Ha! - managed to mess up on first attempt. But threw a few new random MIDI notes into the Beatstep and got the Beatstep Pad 14 (F7) to trigger Bank E, Pad 7 of my SP404sx. Hey, I'll settle for that humble beginning :-) Now to work backwards with the MIDI notes and start again.
FINAL UPDATE: Got it at last. Beatstep pads 1 to 12 (B1 to A#2) leaving Beatstep pads 13 to 16 blank. with the remaining 4 pads playing pads 1 to 4 of Bank B of the sp-404.
That'll do me nicely for now, thanks, everything works great from a cold start away from the computer.
Still plenty to learn about this amazing controller, maybe doing other templates for 404's other banks or for my arranger keyboard, but well pleased at triggering 404's pads with velocity.
Cheers