The IBM System/370 Model 168 and Model 158 were both announced on August 2, 1972. Prior 370 systems had not "offered virtual storage capability, which was to be a hallmark of the 370 line," and some said thatthe 168 and 158 were the first "real 370" products. By contrast, "in 1972, the System/370 Advanced Function was released and had new Address Relocation Hardware and now supported four new operating systems (VM/370, DOS/VS, OS/VS1, OS/VS2)." The 158 and 168 were withdrawn on September 15, 1980.