INT 16 U - PCIBM PC Tools v5.1-8.0 DESKTOP - CREATE/OPEN/DELETE FILE
	AX = FFD4h
	BH = 3Ch create file (with no attributes)
	     3Dh open file
	     41h delete file
	BL = access mode
	     00h read only
	     01h write only
	     02h read/write
	DS:SI -> ASCIZA NUL-terminated ASCII string.	The ASCIZ string "ABC" consists of the four bytes 41h, 42h, 43h, and 00h.  Unless otherwise specified, maximum lengths given in the interrupt list do not include the terminating NUL. filename
Return: BX = file handle
	    0000h on error
Note:	operation is attempted in (in order) the directory from which the
	  desktop was started/run???, the directory specified with the
	  filename, X:\PCTOOLS\, and X:\