Ok, I was trying to understand exactly what the alloc(III) subroutine
does in unix version 5 and I've discovered that the source code for it
appears to be missing.
In Unix v6 there is a file in the TUHS archives
V6/usr/source/s4/alloc.s so I assume there should be a
V5/usr/source/s4/alloc.s as well but I can't find it anywhere.
In v5 the command "ar t /lib/libc.a" lists the files in the c library
and that includes alloc.o so there should be a source file somewhere.
Mark