Hi, Toby here. I have written a Perl module to drive a PC parallel port to do JTAG instruction register and data register shifts, among other things. This is what I have posted on my website. However, it's pretty slow (maybe 10kbs) owing to the slow speed of the parallel port. I have also written another Perl module which drives an <a href="http://www.amontec.com>Amontec JTAGKey which is a USB-based device and therefore much faster. If you're interested in something like that, I can give you the Perl module for that too.