I am new to the forum just purchased a DSL 100 HR brand new and unfortunately Marshall has gotten really minimal with the information that they have put in user manuals there is absolutely nothing I can find in what little information is included in any of the paperwork having to deal with how to use or program the midi footswitch with this amplifier. 
The stock Marshall 6 button midi footswitch for those of us in the United States has been on backorder for a year and a half and unavailable, but I did find a retired electronics engineer that builds and sells the substitute foot switch that he designed himself because he had the same problem. He purchased the same amplifier a year and a half ago and no midi foot switches available. I purchased one of his actually for quite a bit less than the factory ones However, can anyone point me to where I would look to find information regarding programming?