 This keyboard layout was the official layout of typewriters in public administration and most private companies until the mid-1970s, when it began to be replaced by the AZERTY layout.When both layouts were in use the HCESAR was called the ""teclado nacional"" (national keyboard [layout]) and the AZERTY ""teclado internacional"" (international keyboard [layout]).In the early 1980s, when the Portuguese public administration started to replace its old machines with multiuser terminal-based computers, mainly running the Unix OS, both HCESAR and AZERTY were slowly replaced by the QWERTY layout, which is overwhelmingly used today.