Problem - Serial Ports

I’m using QNX 6.4 and an Athena II(Diamond Systems). I’m trying to use the serial ports of one EMM-OPT-XT REV D(Diamond Systems).

To mount the serial ports I use the command devc-8250. ( The serial ports appear on the “dev” as ser1, ser2, ser3…).
The problem is that the use of it is limited, one byte is sent each 50 ms, it’s too slow.
The serial ports of the Athena II works normally, but the ports of the Emerald don’t.
I use the command stty >dev/ser1 to test the serial ports.

There’s any other configuration that has to be set?
Any idea?


Every 50ms sounds like the interrupt isn’t working right.

I’ve tried with all interruptions and still not working. ( is not exactly 50ms )

The byte is sent, but it’s very slow…
There’s any other thing that has to be done? Any command?


Does anybody has any idea?
There’s any option of the devc-8250 that must be set?

(Sorry for my English…)