Dat be de one. Alas for the OP, it doesn't seem to contain any PDP-11 stuff (well, a bit on the RK11-C, etc, but nothing on any processor, at least that I could see). FWIW, it's available online on an indexed, page-by-page basis at: http://www.pdp8online.com/bklatt/TechTips.html Worth looking through. Some of them are amusing, like "Disk Destruction Made Simple" and "DECtape Reels Falling Off Drive". Noel