Xerox 800 Photographic Negative storage

[GeoNomad]

I came across these in my my boxes of stuff and wonder when and where they were used.

They appear to be some sort of storage medium using photographic negatives and are in a sleeve labelled Xerox 800.

They are about the size of punch cards.

Just curious. I don't remember them. But then, there are a lot of things I don't remember any more.

 

[NeXT]

They look exactly like the media used in the IBM Mag Card II typewriters.

https://www.youtube.com/watch?v=H92dJbp-KNM
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