Computer History

The IBM PC/AT
Building on the strength of the PC (1981) and PC/XT (1983), the PC/AT was a major increase in performance and storage capacity. Although it looked like the original PC, Intel's fast 80286 processor running at 6 MHz, combined with 16-bit busses, made the AT several times faster than the original PC. AT systems also came with much more RAM, usually 512 or 640 Kb, and new high-density 1.2 Mb floppy disk drives.

Hard disks of up to 20 Mb became available, and you could even install two if you wanted. The hardware changes meant a new version of DOS (the dreaded 3.0).

The price for an AT with 512 Kb of RAM, a serial/parallel adapter, a high-density floppy drive, and a 20 Mb hard disk was over $5000