It is indeed strange that TimeLine would have used the 50 pin Transport Port, as I have explained that to my knowledge the Alesis would need the RS-422 data lines, and for the Lynx-2 there were no such signals named on the port. Perhaps they were "faking it" by utilizing some pins that were usually assigned to some other function, and changing the meaning of the data lines virtually, i.e. in software.
For those thread readers who may be confused by apparently missing photo (.jpg) images (particularly from timkroeger's post #33, and sweetbeats posts #37 & 38), there appears to be a bug in certain versions of the Firefox browser (Rev. 5) which do not allow viewing of them.
Nothing further is known as of the time of this post about this issue. Firefox is providing no visible clues to the reader that the post contained such images- however other browsers are displaying some indication that the post(s) contain images, even if they are unable to load them currently.
Of course you're right about the specific IC's or even IC families being different. After all, the concept of Application Specific IC's was fairly new for the '80's, such that the Uncommited Logic Arrays and Programmable Logic Arrays you mentioned as being possibly involved were "best in class" for that era.
The overall concept of wide-word parallel to serial conversion for the purpose of quasi-realtime Phase Lock Looping is what I was referring to as similar between the Microlynx and Lynx 1/ Lynx 2 units.
Do you still have the .bin files from your EPROM refresh/copy somewhere? Might be cool to post those up for posterity's sake, as I'm going to try to do just that for my Microlynx when it arrives (and I can get a decent burner purchased).