Format of ASCROLL parameter block:
Offset	Size	Description	)
 00h	WORD	0006h (length of following data)
 02h	BYTE	left-most column (0-based) of source
 03h	BYTE	top-most row (0-based) of source
 04h	BYTE	rectangle's width in character cells
 05h	BYTE	rectangle's height in character cells
 06h	BYTE	left-most column (0-based) of destination
 07h	BYTE	top-most row (0-based) of destination
SeeAlso: #03883