|Check out these no-driver-or-firmware-development-needed USB chips from
FTDI. Choose async serial or byte wide FIFO interface. Basic boards from
DLP are in stock at (engineer friendly) Mouser at $25 each. The 24 pin
0.600 DIP module will mate directly with your socket board. The latest
FIFO flavor chips have a "bit bang" mode where the data port becomes PIO
and a timer regulates byte rate. Use it to load your FPGA they say.