interface was an internal Molex connector). The 1969 RS-232-C standard recommended the DB-25 female connectors for DTE and DCE devices, and male-to-male cables to connect them; this was codified in EIA-232D. The timesharing era from the mid-1960s to the early 1980s relied heavily on minicomputers, modems, printers, and video-display terminals connected by DB-25 cables.

As the EIA-232 standard improved, many of its defined signals became obsolete. Handshaking and secondary channel pins were not used, making