In 1990, Pink became the Object Based Systems group with Senior Vice President Ed Birss and a diverse staff of 150, including marketing and secretaries. Meanwhile, the hundreds of personnel in the Blue design group were constrained by the commercial pragmatism of maintaining their billion-dollar legacy operating system, which required them to refuse many new features, which earned them the infamous nickname "Blue Meanies". This group had well established the evolution of System 6 which would be released in 1991 as System 7. RAM chips and hard drives were extremely expensive so most personal computers were critically resource constrained, and System 7 would already barely fit onto existing Macintosh systems. Pink would therefore be hard-pressed to include backward compatibility for System 7 applications atop itself — assuming the team wanted to do so. This physical and economical constraint is a crucial aspect of the second-system effect.