Years back I remember coming across two different sizes of "male pins" both of which had different sized "female pins" on the D-sub connectors.

 

You had to make sure you had either "large" or "small" matched up, but played havoc with projects if you had the correct ones.

 

So when I went to revisit the issue, there is only one size?   Does anyone remember the odd small/large pin intermittent issues?  I'm thinking 1980's as our lab text had bins clearly labeled, but with a note for the lab to only use on size.  

 

Tom