IBM Personal Computer/AT Intel 80286 microprocessor IBM operating system RAM Intel MS-DOS
In 1984, IBM introduced the IBM Personal Computer/AT (more often called the PC/AT or AT) built around the Intel 80286 microprocessor. This chip was much faster, and could address up to 16MB of RAM but only in a mode that largely broke compatibility with the earlier 8086 and 8088. In particular, the MS-DOS operating system was not able to take advantage of this capability.
