I need to generate a virtual parallel port. of course, there is a driver. Through this driver, when the user access the parallel port like before, the data go out through the usb. How to do it? I see many virtual com port program, but no any virtual parallel port one.
any ideas.
Why don't you just buy one? There are many available for $10US. Just search the internet for "USB to parallel port adaptors". If you need bidirectional, include that in your search.
Why don't you just buy one? There are many available for $10US. Just search the internet for "USB to parallel port adaptors". If you need bidirectional, include that in your search.
In fact I was working on an IDE USB interface, it is so difficult but what I can say that you must learn about the behavior of USB port 'cause it isn't the same of parallel one and then there will be a need to work with a microcontroler.
I think that as a first step you must learn about both of the ports and then you can think about the transmission tool.
it's easy to find out USB-2-Parallel port adaptors but they are only intended to connect an USB port to a centronics connector printer using USB printing support integrated in XP (as USB printer), in other words you have a supporting driver but it's not anything to connect a program dealing directly with parallel port (as opossed to a virtual parallel port). Even at chips manufacturers websites I couldn't found time ago such a driver. Moreover, afaik even USB connected dockstations with generic DB25 connector (just as PC) are not delivered bundled with virtual port driver and have therefore the same functionality as integrated USB-centronics cables.
I think it's a commercial issue: most people only want parallel connectivity to connect a printer and manufacturers don't bother developing a parallel virtual port driver as they do for serial ports. Since at USB side connectivity seems to be standard (all adaptors connect seamlessly with the original XP printing driver) a virtual port driver should works for all pieces (at least at basic functionality) but I don't know if it would be problematic to override the original XP driver for printing (as virtual USB printer)...