MS-DOS 2.11 [TI Professional Computer OEM r2.13] Released in 1984 by Microsoft/Texas Instruments For the Texas Instruments Professional Computer Image Quality: Unused/Unmodified This is the special OEM version of MS-DOS needed to operate a Texas Instruments Professional Computer. This version is labled "MS-DOS 2 version 2.13". It contains IO.SYS 2.13, MSDOS.SYS 2.11, COMMAND.COM 2.11, and support utilities. The 2.13 update includes support for 80-track drives, hard disk utilities, and numerous bug fixes to the support tools. Important: This disk will ONLY boot on a TI Professional Computer. It will NOT boot on an IBM PC, IBM hardware compatible PC, or a PC emulator. This archive contains one 5.25 360k floppy disk image. TI Professional Disks are formatted with an interleave of 1:2 instead of 1:1. If you use a sector copying tool, you must make sure the tracks are formatted appropriately.