On Oct 22, 2012, at 3:32 PM, Dave McGuire wrote: ... The 2.11BSD lib looks leaner, and I am using it in my pet OS project (I pick the pieces I need "on the run", I have not done a complete port... yet). If the above suggestion doesn't get you anywhere, perhaps avrlibc could be hacked into a PDP-11 library. All of the hardware support will have to be ripped out of course, but there are nice tight implementations of generic library functions in there. I took a look at that. It seems to be largely assembly code, which makes it not very helpful. paul