+
+The source for this library can be found at:
+http://git.zerfleddert.de/cgi-bin/gitweb.cgi/usb-driver
+
+The main website is located at:
+http://www.rmdir.de/~michael/xilinx/
+
+The Git repository can be cloned with:
+git clone git://git.zerfleddert.de/usb-driver
+
+
+Notes for the USB cable
+=======================
+
+To use the device as an ordinary user, put the following line in a new
+file in /etc/udev/rules.d/ and restart udev:
+ACTION=="add", BUS=="usb", SYSFS{idVendor}=="03fd", MODE="666"
+
+
+If your cable does not have the ID 03fd:0008 in the output of lsusb,
+the initial firmware has not been loaded (loading it changes the
+product-ID from another value to 8). To load the firmware follow
+these steps:
+
+1. If you have no /etc/udev/rules.d/xusbdfwu.rules file, copy it from
+ /path/to/ISE/bin/lin/xusbdfwu.rules to /etc/udev/rules.d/xusbdfwu.rules
+
+2. Install the package containing /sbin/fxload from your linux distribution.
+ It is usually called "fxload"
+
+3. copy the file /path/to/ISE/bin/lin/xusbdfwu.hex to /usr/share/xusbdfwu.hex
+
+4. restart udev and re-plug the cable
+
+
+Notes for the parallel cable
+============================
+
+To access the parallel port from userspace, the kernel needs to be built with
+the features "Parallel port support" (CONFIG_PARPORT), "PC-style hardware"
+(CONFIG_PARPORT_PC) and "Support for user-space parallel port device drivers"
+(CONFIG_PPDEV) builtin or as modules. If these features are built as modules,
+they need to be loaded before using this library.
+These modules are called:
+parport
+parport_pc
+ppdev
+
+
+To use the device as an ordinary user, put the user in the group 'lp'
+
+
+If you have an almost compatible cable which works with other software but not
+with Impact, try adding -DFORCE_PC3_IDENT to the CFLAGS line in the Makefile.
+This enables a hack by Stefan Ziegenbalg to force detection of a parallel cable.
+
+
+Parallel Cable IV is currently only supported in 'compatibility mode', as no
+attempt to configure the ECP registers is done by this library.
+
+
+If you get "Programming failed" or "DONE did not go high" when programming
+through the parallel cable with Impact 9.1, make sure to have the option "Use
+HIGHZ instead of BYPASS" enabled in Edit -> Preferences -> iMPACT Configuration
+Preferences.
+If you are using batch mode, add the following line to your cmd file:
+setPreference -pref UseHighz:TRUE
+(This problem also occurs on windows and when using the real windrvr in linux
+and is solved with the same workaround. Impact 8.2 is working fine with the same
+boards and designs)
+
+
+Notes for FTDI 2232 based cables
+================================
+
+To build the driver with FTDI 2232 support, you need to have libftdi and
+the libftdi development package installed. On debian, you can install both
+by installing 'libftdi-dev'.
+
+To set-up the device:
+1. Find out the vendor and product id of your cable using lsusb:
+ Bus 003 Device 005: ID 0403:cff8 Future Technology Devices ...
+ ~~~~~~~~~
+
+2. Copy the sample libusb-driverrc to ~/.libusb-driverrc, edit it and replace
+ the vendor and product-id in the example file with the values provided in
+ the lsusb-output. You can also change the 'parallel port' which is mapped to
+ this cable. Impact sees the device at that port as a Parallel Cable III.
+
+3. To use the device as an ordinary user, put the following line in a new file
+ in /etc/udev/rules.d/ and restart udev:
+ ACTION=="add", BUS=="usb", SYSFS{idVendor}=="0403", SYSFS{idProduct}=="cff8", MODE="666"
+ (replace the vendor and product id with your values)
+
+The support for FTDI 2232 based devices is experimental and they are currently
+significantly slower than the other supported cables.