Re: cannot talk with AT modem
On Sun, 23 Jul 2000, Tomasz Barszczak wrote:
> I have just installed slink on my AMD Athlon PC.
> I have an internal USR 56K modem model 2977.
> It is not a winmodem, it uses Hayes AT language.
> Under Windows 98 it is recognized at COM5 and works fine.
> First problem was that in /dev there were only ttyS0-ttyS3 (COM1-COM4)
> with major number 4 and minor numbers 64-67.
> I have created by hand ttyS4-ttyS7 character devices with minor numbers 68-71,
> and same owner, group and permissions and ttyS0-ttyS3.
> I hope they correspond to COM5-COM8.
> However when I run minicom with /dev/ttyS4 I cannot talk to the modem.
> It does not respond to "at", pressing enter, etc., no characters are echoed.
> wvdialconf scans my serial ports, finds active ports at ttyS0 and ttyS1
> (COM1, COM@) with no modem there (it tries to send AT commands),
> then continues with port scan of ttyS2-ttyS7 without even attempting
> to send AT commands, i.e. I guess it did not find active serial ports there
> at all.
> Does anyone know what I can do?
As a metter of fact, there are up to four physical communications ports on
a normal PC. The reason to have devices like COM5 under windows is that it
represents a non-default port configuration by assigning it a new
number. In Linux you have the "/dev/ttyS[0-3]" devices which represent
your physical ports. You can change their configuration (IRQ+I/O base) via
setserial. See the manual page.