Alan B. Pearce wrote: > You really need to do all three rows if you wish to provide holes on > 0.1" x > 0.1" pitch, as there are two variations of the connector which have two > rows of pins. One version is the 3 row connector body with the centre > row missing, and the other is a narrower one with only two rows. I > would be tempted to provide three rows of holes, but only bring out the > two nearest the edge of the PCB to pads as that is the form of the > second connector above, but if people insist on using the other one > they can fit it, or the three row version. I asked this on Friday and didn't get an answer, so I went ahead with what seemed reasonable to me. I needed to get this mostly done over the weekend. I ended up leaving pads for the two row "type B" connector. These were the most common ones I found in Google searches, and are really bigger than seems necessary for a board of this type. I brought the two rows of 32 pins each out to two rows of pads, and made sure the pads were back far enough so that simple shrouded headers like Wouter's connectors could be used without covering the access pads. This just left room for 50 columns of pads in the prototype area. Due to the extra board height, there was room for two 14 pin SOIC footprints such as is common with opamps, many of which are not available in DIP. The access pads for the two SOICs are in addition to the prototype area. > I think you may fine that compatible ones are available in certain > marketing areas of the USA, in specific markets of rack mount gear, > unless the VME style card has the market share. I frankly don't see a lot of card-cage rack mounted equipment anymore. > However if you wish to > market in Europe then being able to say it is Eurocard form factor and > connector compatible will help you. Guess this depends on how big you > see your market. Well the board is 160 x 100 mm and it has the footprint for the type B Eurocard connector on the right side. I noticed that I didn't exactly get flooded with answers when asking specifics about Eurocards, so I'm not sure how important this feature is. Hopefully I've done enough to make it at least somewhat usable in that role. ***************************************************************** Embed Inc, embedded system specialists in Littleton Massachusetts (978) 742-9014, http://www.embedinc.com -- http://www.piclist.com PIC/SX FAQ & list archive View/change your membership options at http://mailman.mit.edu/mailman/listinfo/piclist