IBM PS/2 Model 55SX

A desktop Micro Channel machine built around the 386SX, the cut-down chip that gave 386 instructions on a 16-bit bus. That combination made it IBM's volume business PS/2 and a common OS/2 workstation, so surviving examples often carry period software and adapters. The 55 SX is the easiest way into Micro Channel: small enough to shelve, plentiful enough to be affordable, and it takes the same reference-diskette configuration dance as its larger relatives.