use POSIX;

$path = shift or die 'no path';

#system "stty 230400 cstopb raw";
#$? or die 'failed to stty';

$chans = '';
$chans .= v42 for (1..512);

$fd = POSIX::open($path, &POSIX::O_RDWR);
warn "FD $fd";
$fd or die 'no fd';
POSIX::tcsendbreak($fd, 0) ;
POSIX::write($fd, v0, 1);
POSIX::write($fd, $chans, length $chans);