On 7 Apr 2004, Lars Brinkhoff wrote: [snip] [snip] Absolutely fabulous reading! The best part, in my opinion, is that when he is walking you through the code of a function and you come to another function call, he gives you a short description (sometimes just a couple of words, sometimes a few sentences) of what that other function does so you can just keep on reading the one you're in. Since most time-space tradeoffs were made in favor of saving space and spending time (64k limit for all kernel code and data on the 11/40), the code is fairly straight forward (for example, linear searches instead of hash tables) once you grok the magic of process switching and how system calls work, which Lions helps with a lot. He also gives a brief introduction to enough PDP-11 assembly and architecture, and C, to understand the magic. I found it to be a very pleasant read a few years ago and I plan to read it again one of these days. Andru -- Andru Luvisi Quote Of The Moment: Heisenberg may have been here.