@kenshirriff I learned this week from Scott Manley that these packages are not ICs in the sense we know (though 7400 series TTL was around from the early 70s). These are packages of a small number of discrete transistors wired up inside. I.e. All the components weren’t fabricated together on a single silicon substrate. These type are attributed to IBM I think he said. It’s very much a product of the space programme.