Using internal modem cards with SCO Xenix

[Jonathan Bayer]

In article <5101 at viscous.sco.COM> rosso at sco.com (Ross Oliver) writes:

}The reason you are having problems is that your internal modems cannot
}be set to use interrupts other than IRQ3 or IRQ4.  For a serial device
}to work under XENIX, it must be configured on its own interrupt vector.
}IRQ4 is allocated to COM1, and IRQ3 is for COM2.  Since MS-DOS does not
}use interrupts, manufacturers of serial cards have taken the I/O ports
}used by COM1 and COM2, and simply extended them on up through the I/O
}space, thus producing COM3, COM4, COM5, etc. (I've seen some cards that
}claim to go up to COM10).  However, since XENIX requires interrupts as
}well as the I/O ports, most of these modems and serial cards won't work
}under XENIX above COM2.
}
}However, if you can set these boards to use other interrupts, then you
}can use them alongside existing COM1 and COM2 devices.  To do this, you
}will have to modify the /usr/sys/conf/master file to tell the serial
}driver to handle the additional interrupts.  Modify the "vec3" and "vec4"
}columns for the "sio" entry, then rebuild your kernel.


OK.  Since each device must have it's own interrupt, why not make two
serial ports both use the same interrupt, and modify sioconf.c to show
that the second serial port is nothing more that a second port on the
first serial card?  For these serial cards that go to com 10 (or
whatever), why not simply set up all the ports on the card to use the
same interrupt, and set up sioconf properly (specificaly the port count,
the interrupt vector, the base address of the board, the interrupt poll
address, and the spacing of the io ports on the board).  The only
potential problem is the interrupt poll address (as I see it)


JB
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