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.

See also: 214402

214403 - PGS1600.DEV - IOCTL - SET CONFIGURATION???