The 5-pin DIN keyboard connector used with the first IBM PC (1981) and second-generation IBM AT (1984). It was subsequently replaced with the smaller 6-pin Mini-DIN connector on the IBM PS/2 in 1987.

The height and width of this new mini-DIN connector have each been reduced by 23%, and the footprint area has been reduced by 25%. The size reduction makes the KMDR series connectors well-suited ...

It connects to the keyboard using the original mini-DIN connector, and is housed in the classic Altoids tin enclosure. Since the protocol used by NeXT isn’t standard, they had to figure it out ...