This was prompted by a question on the electronics site (which was asking why only an open collector variant of a particularly old part existed and how it could be part of a data bus).
This was a pretty important development as it revolutionised bus interfacing (such as memory systems) among other things.
I know that 3 state (tri-state in National Semiconductor parlance which was [is?] trademarked) came out sometime in the (early) 1970s but I am trying to pin it down to at least a year range.
I have tried searching for the date of the trademark without success so I am asking this here in the hope people here might remember their first parts with this feature.
I have found a citation at ACM from 1978 that references this, but I am not sure if actual parts were in the wild prior to this. My first parts using this were in the early 80s (so I know it existed by then).
Note that I am looking for the first commercial implementations.
I would appreciate any insight.