IBM Soft Touch Keyboard
Provided by the ASK Keyboard Directory

aka IBM Enhanced Keyboard with Soft Touch
eg, P/N 8184692
Lexmark-made 101-key (ANSI) only Enhanced Keyboard intended for IBM RISC System/6000 workstations. This variant is unique for having their buckling springs factory-greased, which most notably dampens the springs' ability to resonate and create ping after clicking whilst not muting the click itself. Being an IBM RISC Systems Enhanced Keyboard, it has an internal speaker and requires a specific SDL to PS/2 cable with the normally unused pins (for PC-compatible keyboards) present for driving the speaker.