Here's the beginning of the entry for 'box' in the 1991 book "The New Hacker's dictionary at https://archive.org/details/newhackersdictio00raym/page/76/mode/2up

Here's the beginning of the entry for 'box' in the 1991 book "The New Hacker's dictionary at https://archive.org/details/newhackersdictio00raym/page/76/mode/2up?q=box https://archive.org/details/newhackersdictio00raym/page/76/m... : > box n. 1. A computer; esp. in the construction foo box where foo is some functional qualifier, like 'graphics', or the name of an OS (thus, UNIX box, MS-DOS box, etc.) "We preprocess the data on UNIX boxes before handing it up to the mainframe." (It is not in the 1983 book "The Hacker's dictionary : a guide to the world of computer wizards".)