Kermit and Comms prob

[James Brelsford]

I'm trying to set up serial comms (for show and tell, don't ask) between two C360's using Kermit as the terminal emulator. I've got Kermit running on one machine and just the OS (10.20) on the target sys and I'm trying to log in via the serial port. The kermit sys is displaying what I'd expect to see from the other machine ok, but when I hit enter to try to log in I get no response from the target machine.

I've tested the cable useing a NT machine and I can log into the target sys fine. I hooked the Kermit sys to the NT machine and I can pass chars fine between the two machines. What I cann't do is get one C360 to log into the other. Any ideas???

[A. Clay Stephenson]

Oklay James, do you have a getty running on the serial port; i.e. is there an entry in /etc/inittab for the serial port and is it set to respawn?

[Anthony deRito]

James, go into SAM -> Peripheral Devices -> Terminals and Modems. Check out device file for your trying to communicate with then validate your /etc/inittab file to see if you have an entry in there to respawn a getty process for that terminal device file. Any changes you make be sure to run init -q. Check also with ps on the getty.

[James Brelsford]

Thanks for the replies.

The line in INITTAB that references the port that I'm using is as follows;
a1:2:off:/usr/sbin/getty -h tty1p0 2400

If I understand the Inittab man page, the OFF will kill the terminal process. So is this the entry that I should change to respawn?????

[A. Clay Stephenson]

Yes that isd it. Note the 2400 entry at the end. That matches a tag in the /etc/gettydefs file. You may want to link to another tag e.g. 9600. Bear in mind, that most of the gettydefs 'loop around' trying 2400, then perhaps 4800, and so on. You probably want to point to one that does not change baudrates. If you like, you can use SAM to configure this
port. Simply add a Terminal.

[Bill Hassell]

Yes, :off: says don't start any login process on this port, whereas :respawn: means to start getty when nothing is active on the port.

Note also that RS-232 cables are very easily confused: there are 2 types, straight through (called a modem cable) and crossover or null-modem which are used with printers and peer-to-peer connections.

With a lot of time and documentation or a DVM to check voltages and continuity, you could figure out what you need. Or a lot easier: get a null-modem adapter (they come in 9-9 pin and 25-25 pin). If something doesn't work, insert the null-mode adapter and try again.