SL-2001 - In edit mode, select the "Memory used" function (press function switch 1 twice) Adjust slider 4 until it reads 'erase all'. Press 'alpha switch' to erase. When I did this it eliminates the memory error, but then I got no activity though it appears 2001 is selected on the zones and they are full width midi channel 1. Setting this unit up to xmit from the keys is quirky. I tried running signals in and saw that the midiscope (ie. in edit mode the upper left function) was working. Then selected 'in A' instead of '2001' and could see it bouncing the midi messags on the 'scope' also to out A, B, C, D when I selected those with slider 2 which now had an editing option! Now, when I selected 2001 again..it just worked on that same port. But if..say before selecting 2001 you have out A turned off, then it assumes that for the keyboard also. It seems an oddity that they didn't allow you to patch the ins and outs and then allow you to independently select the output FOR THE 2001's keyboard!! And perform a software merge! Crazy. But no if 2001 is selected as the source then there's absolutely no way to edit what it's routed to. You have to select rather one of the inputs and associate it to an output. VEry confusing!