Serial port control details


is there any more detailed description of the functionality of devctl
for the PC built in serial ports (modem control signals etc)? I have
tried to look into the sources in CVS and the supported functionality
seems to be less than the devctl_char.h include file. I am not sure what
the “timed” parameters mean and if they are supposed to work or not.

I have 2 simple goals:

  • sensing input modem signals such as DCD and the DDCD bits in 8250 MSR
  • controling DTR and RTS signals (this seems to be achievable, I
    actually need to raise these for about 100ms and lower them again).

Any hint welcomed.

Petr Novak <>
ICZ a.s.
V Olsinach 75
CZ-100 97 Praha 10
Ph: +420 2 8100 2222
Fax: +420 2 8100 2244