The Logic Off Topic list

Hello!! I'm trying to set up my environment in Logic to control my keyboard. I've been using different guides, but none of them seem to go deep enough for me into SYSEX. Or maybe it's just not sinking in. The problem I'm having now is that I'm sending midi data to Logic so that maybe I could see the SYSEX data and become familiar with it. When I dump it into logic though (I'm just dumping one preset-Concert Grand) I only understand or recognize part of the message. I understand the id, etc.. and I recognize Hex but after every line there are some symbols that I have no clue what they are. For example one line may be:
$40 $00 $00 $01 $43 $00 @...C.
   What is the @...C. ?!?!?!?!? After some other lines there may be Z...I. or O.@.!. or @.@.@.
   I'm confused. I called E-mu (I'm using the E-mu proteus mps plus keyboard by the way) and they couldn't help me. They have no listing of these symbols. 
  How am I supposed to know which line affects Alt Envelope or tuning etc...?
  The E-mu tech told me that I should just get Soundiver which should do this for me. I'm sure Soundiver is a kick-ass program. I've heard so many great things about it. But, it's just not an option for me right now for financial reasons. So I have to do it the ole' fashioned way. 
  I really appreciate any help. Thanks in advance!!
              --Roger


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