Basic MIDI understanding
To begin, you must setup the communication channel to be the same so both machines can talk to each other. Your USER manuals should have some info. on that, too. Let's say you have that setup already; then
When you bring up a drum patch on the EPS, it must be (by default) in a drum channel mode. This means that the instrument is able to play multiple samples (different drum sounds) on different keys. Various manufacturers handle this differently, but it amounts to the same thing.
So when you play the drum patch, everything sounds fine.
Now, when you want to record events you play into its sequencer, some sequencers force you to record drum patches into channel 10. More advanced sequencers will allow you to record into any channel, so long as any channel can be designated a "drum" channel.
Channel 10 is the MIDI spec for General MIDI (GM). So if you record a MIDI file and give it to your friend to play on his computer, the drum patch must be on channel 10, or the drums won't sound.
For this example, we're using the EPS' sequencer:
To setup your situation to record drums and chords at the same time, you'll need to MIDI the 2nd board into the EPS. That is, MIDI OUT your "2" board into the MIDI IN of your EPS.
Make sure the chords and sounds you like on your 2nd board are playing into a designated channel on the EPS sequencer when it is in RECORD mode.
Make sure the Drum patch on the EPS is also playing on its particular channel in RECORD mode.
If you can get those to sound properly, you should be able to hit RECORD and play both keyboards and the EPS sequencer will record the events from both keyboards at the same time.
BUT, to play the chord sounds on the 2nd board when you hit PLAY on the EPS sequencer after recording, you now must have the MIDI cable hooked up correctly from the EPS back to your "2" board. Thus, MIDI OUT from the EPS back to the MIDI IN of your "2".
It can seem to get confusing, but the more you think about it and setup your "wiring" correctly, it will begin to get easier.
