From the referenced 2014 Gearslutz thread:
I think the OS 1.31 Addendum is pretty direct as to what the function does--for the most part. While the description might allow for multiple interpretations for the implementation of "rechannelize," I think the "Block Diagrams" add far more details about how it is implemented.
The LCD (24 x 2) really doesn't explain it at all:
RECHANNELIZE INPUT
To Track Destination: [off/always/on record]
Looking at just the panel and without knowing that the sequencer only records one track at a time (the destination track), I can easily infer that rechannelize could mean, "Hey, XL-7, take incoming multichannel midi data and put it into different tracks."
Perhaps there were a number of feature requests/comments based on this and so in OS 2.0 the explode/combine features were added as (after-the-fact) editing options (as opposed to real time input filtering).
Explode/Combine Tracks (excerpts from the OS 2.0 Addendum):
"These new functions facilitate the interchange between single multichannel
tracks and multiple single-channel tracks. Both of these functions
use the clipboard as the intermediary step in the conversion."
"If the destination track isn’t set to Multi A or B, the track will play back rechannelized
onto a single MIDI channel. Select MultiA or MultiB to play back multiple MIDI channels on
a track."
In the Addendum to OS 1.31, there is a paragraph that is open to misinterpretation if someone comes to the E-Mu sequencer from software or hardware that allows for multiple tracks to be recorded simultaneously.
"This new screen has been added to the MIDI menu. This feature makes it
easier to record to the internal sequencer using an external keyboard.
Rechannelize Input changes the channel and destination of incoming
MIDI data according to the settings in the Channel Assignment screen."
"To record multiple tracks, you simply change the track number and preset.
You don’t have to change the channel number of your external MIDI
controller."
"Rechannelize Input can be set to Off, Always or On Record. When set to
On Record, the input will only be rechannelized when the Record LED is
illuminated (Record or Record-Pause mode). This allows normal MIDI
channel routing except when recording, when the channel data will be
changed to match the current track."
The middle paragraph above refers to recording multiple tracks sequentially.
With the new rechannelize feature, users can set the channel for the [single] destination track in a new way from the previous OS. Let's say I use an external keyboard set to transmit on midi channels 1 to record track 1. With Rechannelize = on record, once I "simply change the track number and preset" to record a second track, even though my keyboard is sending midi data on midi channel 1, the E-Mu sequencer will rechannelize the data to match the track number.
Then when OS 2.0 came along, I should then have gotten the ability to take a pattern with 16 single channel rechannelized tracks and use the new clipboard features (combine, specifically), to make a single multi-channel [MIDIA or MIDIB] track, thereby freeing up other tracks.
As I said in the previous post, too bad OS 2.0 was the last OS and we never got the benefit of new features--such as "Filter Incoming Data" [off, always, on record]. :-(
Every so often I think of contacting a current gear manufacturer with thoughts on a new-and-improved-yet-reverse-compatible clone of our beloved abandoned/legacy E-Mus. I'd definitely suggest adding real time filtering.
BTW, I don't know if you do any DIY circuit building/programming, but with my admittedly extremely limited experience with an arduino project, I have no doubt an external midi channel filter could be created. Also, if my parallel port midi interface worked under Windows 10, I am sure the accompanying software could handle the channel-by-channel filtering. Its unfortunate that you can't choose which channels to send your E-Mu from the other gear.
Steve