Many programs use the TERM variable and the database /etc/termcap or /usr/lib/terminfo/* to decide which strings to send for clear screen, move cursor, etc., and sometimes also to decide which string is sent by the users backspace key, function keys etc. This value is first set by the kernel (for the console). Usually, this variable is re-set by getty, using /etc/ttytype or the argument specified in /etc/inittab. Sometimes, it is also set in /etc/profile.
Older systems use TERM=console or TERM=con80x25. Newer systems (with ncurses 1.8.6) use the more specific TERM=linux or TERM=linux-80x25. However, old versions of setterm test for TERM=con* and hence fail to work with TERM=linux.
Since kernel version 1.3.2, the kernel default for the console is TERM=linux.
If you have a termcap without entry for linux, add the word linux to the entry for the console:
and makeconsole|con80x25|linux:\
/usr/lib/terminfo/l/linux a copy of or symbolic link to /usr/lib/terminfo/c/console.
The terminfo entry for the linux console from ncurses 1.8.6 misses the entry kich1=\E[2~, needed by some programs. Edit the file and tic it.