INT 2fH 4800H: Is DOSKEY.COM Installed?

                                                         Compatibility: 5.0+ 
 Expects: AX    4800H
 Returns: AL    status: 00H = Doskey is not installed
                        else= Doskey is installed
    Info: Checks to see if the DOS 5.0+ DOSKEY.COM keyboard utility has
          been installed and is resident in memory.

          The only access to Doskey services is via INT 2fH 4810H, which
          will get a line of text input (using Doskey editing keys) and
          expand a string of text into its Doskey-macro equivalent.

See Also: INT 2fH 48xxH (Doskey Functions)
          INT 2fH: Multiplex Interrupt
          DOS Functions