INT E0 - DR Multiuser DOS - "A_WRITEBLK" - WRITE STRING TO AUX DEVICE
	CL = ADh
	DS:DX -> character control block (see #04051,#04052)
Return: AX = number of characters written
Notes:	does not return until at least one character has been written
	also supported by REAL/32
SeeAlso: INT E0/CL=04h,INT E0/CL=A5h,INT E0/CL=ACh