IBM experimented with a lot of names and Marketing
techniques. These names come immediately to mind
PC,PS/2,Ambra,PS/1,Aptiva,PS/ValuePoint
but there may be others (!). The basic technology
overlapped considerably on some models, IE not all
machines were unique... industry standards were
always important... The PS/2 may have been the most
unique, but as others have pointed out evan that had
a few ISA bus machines.
John A.