When it comes to parallel port adapters, I haven't needed to use such equipment in a long time, so I'm not sure if the programs are installing drivers for direct access to registers or if they are using normal WIN32 API for controlling programmers etc. Obviously, anything that expects direct access will fail for any USB-to-xx adapter.


I guess you are thinking about the PCI latency timer issues and bus mastering.

For things that can work with PCI-connected parallel ports, there is always the possibility of using a PC-card or Expresscard to get a parallel port on a laptop. But the cost of the adapter may be high enough that it is better to replace the parallel equipment.