Okay, retrocomputing nerds: anyone recognize this weird-ass midplane I've had kicking around? Probably old IBM equipment.
Boost if you think it will help.
@phooky What does the other side look like?
@ardgedee both sides are pictured! (The back looks a lot like the front.)
@saper @phooky That's as likely as anything I could come up with. It's also possible it's an analogous product for an IBM competitor's systems, since it physically doesn't resemble IBM's SLT products.
Searching on the item number (1488503) doesn't bring up anything useful, which is kind of unusual for old mainframe hardware.