In cas this may help.
For experimenting with the 20 pin extention of Primer2 and EvoPrimer, I use a standard 20 pin to 20 pin flat cable and a 20 pin IDC Ribbon Cable-to-breadboard adapter. This male adapter is rows spaced 0.3" apart to plug into standard solderless breadboard.
It is sold by
http://www.technologicalarts.ca/catalog … Path=38_42
Regards