If you search for "Roland A-37 Manual" you find the official site with two links. One of them is to some sort of weird doodling (literally) and the other is to the MIDI Implementation. Not sure how or when I found this manual but the file is dated October 30, 2022.
I also wanted to post my own write-up of how to save settings into its memory. This is a super powerful unit that I bought from Guitar Center back in maybe 2003 for $600 USD. I used it as a straight MIDI controller for years before I got into hardware and started realizing some of the great features it has, like being able to send MIDI via two separate MIDI OUT ports and sending one channel for the upper part of the keyboard and a totally different one for the lower part. You can even send on MIDI OUT A on the upper part and MIDI OUT B on the lower part.
Patches
A patch contains things like MIDI channel settings for the upper and lower range of the keyboard. You can select the same channel for both but it’s kind of a waste. A total of 64 patches can be set for each A and B. Patch numbers are from 11-88. Think of the first number as a bank, the second number as a patch number.
Setting the MIDI channel
Ensure none of the EDIT buttons are lit (CONTROL, DATA, PRG CHG)
Select a patch by pressing A/B, then two numbers (A11 is default)
Press UPPER or LOWER to select keyboard MODE you want
Push the DATA edit button. You should see "ch" flash and then it will show the MIDI channel number (1-16) and MIDI OUT socket (A or B)
Use the UP and DOWN buttons to select MIDI channel and out socket (e.g., 7A is channel 7 sent through MIDI OUT A)
You can also push the other button (UPPER or LOWER) to set that channel and socket as well.
Push DATA again to exit
Saving MIDI settings to a patch
Hold the WRITE button
Push the A/B button to select either A or B
Push 1-8 to select the bank
Push 1-8 again to select the memory
Press ENTER to save
Example: Selecting "A" with the A/B button, then pushing the "3" numeric key, then the "2" numeric key would save it in memory slot "A32"
NOTE: release WRITE at any time before hitting ENTER to cancel.
EDIT: here's a link to the Roland A-37 manual