If I remember correctly, you buss pins BC1, BD1, BE1 and BF1... With a Q/CD backplane, that would mean just four sets of wires down the AB side (BC1-BC2-BC3, etc, BD1-BD2-BD3, etc, etc) For a Q/Q backplane, that would mean BC1-DC1-DC2-BC2-BC3-DC3, etc (maintaining the serpentine) BD1-DD1-DD2-BD2-BD3-DD3, etc... BE1... BF1... or you could do what I did... bus the AB and CD sides separately, then wire-wrap one slot AB<->CD... Also, when I did it, I went down to one of the Digital Stockrooms and picked up some specialized 'power strips' which were generally used for bussing DC on the backplane, but could also be used to connect signal pins. It was a copper strip which had alternating pin-sized holes and large holes which wouldn't contact the pin... Perfect for connecting corresponding pins of successive backplane slots... Megan Gentry Former RT-11 Developer +--------------------------------+-------------------------------------+ | Megan Gentry, EMT/B, PP-ASEL | Internet (work): gentry zk3.dec.com | | Unix Support Engineering Group | (home): mbg world.std.com | | Compaq Computer Corporation | addresses need '@' in place of ' ' | | 110 Spitbrook Rd. ZK03-2/T43 | URL: http://world.std.com/~mbg/ | | Nashua, NH 03062 | "pdp-11 programmer - some assembler | | (603) 884 1055 | required." - mbg | +--------------------------------+-------------------------------------+