The Personal System/2 was IBM's failed attempt to regain full control of the PC market by introducing a new, advanced, but proprietary Micro Channel Architecture. The market decided to largely ignore it and follow the clone builders instead.
This is, however, the origin of the PS/2 keyboard/mouse connectors, and the VGA video interface standard.
The Model 30 was not really a "proper" PS/2. It was not based on the new Micro Channel Architecture, but rather on the old PC/XT design. It was in essense just a beefed up PX/XT package up in a PS/2 style case.
Date: 1987