Write n characters to the virtual display
void SLsmg_write_nchars (char *s, unsigned int n);
SLsmg_write_nchars writes at most n characters from the
string s to the display. If the length of s is less
than n, the whole length of the string will get written.
This function differs from SLsmg_write_nstring in that
SLsmg_write_nstring will pad the string to write exactly
n characters. SLsmg_write_nchars does not perform any
padding.
SLsmg_write_nchars, SLsmg_write_nstring