INT 14 - I1541 - SEND A BYTE TO A DEVICE                                        
	AX = 400Ah
	BL = byte to send
	CL = last-byte flag
	    00h more bytes follow
	    01h this is the last byte to be sent
Return: CF clear if successful
	CF set on error
	    AL = error number (see #00354)
SeeAlso: AX=4000h,AX=400Bh