The letters actually refer to the connector shell size and are really independing of the number of pins. For example, a DB shell could have fewer than 25 pins. Some have two or even three heavy pins (one for power, 2 for return) and some signal pins. The reason the the 9-pin is designated DE is because it was developed after A, B, C, and D, sizes.
NASA's Orion Flight Software Production Systems Manager Darrel G. Raines joins Planet Analog Editor Steve Taranovich and Embedded.com Editor Max Maxfield to talk about embedded flight software used on the Mars on EE Times Radio. Live radio show and live chat. Get your questions ready.