INT 21 - PGS1600.DEV - IOCTL - SET CONFIGURATION???
        AX = 4403h
        BX = file handle for device "PGS1600$"
        CX = 0018h (size of buffer)
        DS:DX -> configuration buffer (see AX=4402h"PGS1600")
Return: CF clear if successful
            AX = number of bytes actually written
        CF set on error
            AX = error code (01h,05h,06h,0Dh) (see AH=59h)
Note:   PGS1600.DEV is a device driver for the Cornerstone Technology PG1600
          display adapter, which provides a 1600x1200 monochrome display as
          well as one of two emulations, MDA or CGA.