How do I add more PTYs?

For Solaris 7 and earlier, add a line in /etc/system that says
set pt_cnt =
where is the number of PTYs you want. Halt the system, and do
a "boot -r".

Solaris 2.x supports more than 3000 ptys. The default is 48. Solaris 8
and later create new PTY's as they are needed.