ThinkPad COMDEX BMW IBM
IBM introduced its successful ThinkPad range at COMDEX 1992 using the series designators 300, 500 and 700 (allegedly analogous to the BMW car range and used to indicate market), the 300 series being the "budget", the 500 series "midrange" and the 700 series "high end". This designation continued until the late 1990s when IBM introduced the "T" series as 600/700 series replacements, and the 3, 5 and 7 series model designations were phased out for A (3&7) & X (5) series. The A series was later partially replaced by the R series.
