The PS/2 reference disk functioned like the Systen 7 enablers. The drivers for the onboard hardware (serial ports, video, ect) were all strored on the disk. The critical piece were the Micro Channel card drivers known as ADF (Adapter Description File). Without it the MC cards would not work.

I used as PS/2 Model 70 and a PS/2 Model 80 and both were good computers. OS/2 2.0 would not load on my PS/2 80. SOmehow IBM shipped it with an old obsolete SCSI card and eventually they replaced it so I could load OS/2!