Direct from the mouth of Jukka Marin:
> 
> I ran out of process table entries today when testing screen.
> 
> I had kernel configured for 48 users (changed that to 64 today) which
> should allow for 788 processes; param.c:
> 
> #define NPROC (20 + 16 * MAXUSERS)
> 
> My Makefile correctly lists the MAXUSERS value (now set to 64):
> 
> PARAM=-DMAXUSERS=64
> 
> However, when compiling the kernel, I never saw this symbol being defined
> on the command lines.  I don't know how the Makefile is supposed to work,
> but obviously MAXUSERS isn't being set correctly and the size of process
> table is set to a MUCH smaller value than I expected.
> 
> I think I will manually edit the Makefile to get a new kernel, but this
> problem should be fixed, IMHO (in case it's a real problem and not me
> doing something wrong).

If your running a 1.0 kernel, you can modify that parameter with the command
sysctl -w kern.maxproc=<max proc. you want>

Ron