DIY Xilinx Parallel Cable III (DLC5 JTAG)
This is a simple JTAG interface, which can be connected to computer's parallel port. It is originally designed by Xilinx to program FPGAs and CPLDs. I found the schematics here. I redesigned it to use surface mount electronic parts. It is a one-sided PCB, the bottom side is made from wires. Schematics, Gerber files and Eagle files can be downloaded here: dlc5_jtag.tar.gz or dlc5_jtag.zip.
Schematic of JTAG interface: