See this discussion:
http://www.edaboard.com/viewtopic.php?t=114946&start=0&sid=a0a224571f1ee79470ea7fd2cdb6dbd2 Just keep the same USB chip (FT245BL) to maintain driver compatability with Altera Blaster products. Also you'll need to flash correct PID/VID into the EEPROM so that the correct driver is used. Then load up the CPLD with the code that does the serial<->parallel conversions.
You can find schematics online that show how the chips are physically connected, however Altera does not provide the CPLD logic. There exists some open source logic that functions similarly though.