MEM 0040h:007Bh - PARALLEL DEVICE 4 TIME-OUT COUNTER (pre-PS, PSIBM PS/2, any model Models 25,30)
Size:	BYTE
Note:	Under DR-OpenDOS 7.02+ this setting can be changed with the
	  undocumentedInformation about a product which is not publicly available from the manufacturer, and must be determined by reverse-engineering (disassembly, trial-and-error, etc.).	 Undocumented information tends to change -- often dramatically -- between successive revisions of a product, since the manufacturer has no obligation to maintain compatibility in behavior which is not explicitly stated. CONFIG.SYS LPT4=(port_address|logical_no)[,[timeout]]
	  directive, where port_address = 200h..3FCh, logical_no = 0 or 1..3,
	  timeout=0..255 (default 20).  To avoid any interference with the PS/2IBM PS/2, any model
	  and later interpretation, this will be rejected if this entry does
	  not hold 0, which would indicate it is used for different purposes.
SeeAlso: MEM 0040h:0078h,MEM 0040h:007Ah,MEM 0040h:007Bh"INT 4Bh"