NAME    [Toc]    [Back]

     rtfps - multiplexing serial communications interface

SYNOPSIS    [Toc]    [Back]

     rtfps0 at isa? port 0x1230 irq 10
     com* at rtfps? slave ?
     or
     pccom* at rtfps? slave ?

DESCRIPTION    [Toc]    [Back]

     The rtfps driver provides support for IBM RT PC boards  that
multiplex together
 up to four RS-232C (CCITT V.28) or RS-422A communications interfaces.


     Each rtfps device is the master device for up  to  four  com
devices.  The
     kernel  configuration  specifies  these com devices as slave
devices of the
     rtfps device, as shown in SYNOPSIS.  The port  specification
for the rtfps
     device  is  used  to  compute the base addresses for the com
subdevices.

FILES    [Toc]    [Back]

     /dev/tty0?

SEE ALSO    [Toc]    [Back]

     com(4), intro(4), isa(4)

HISTORY    [Toc]    [Back]

     The rtfps driver was written by Charles Hannum, based on the
ast driver.

BUGS    [Toc]    [Back]

     The rtfps driver is unlikely to work on non-EISA and non-PCI
machines.
     The ISA bus only asserts 10 I/O address lines, and  this  is
not enough.

     Even  on  EISA and PCI machines, some address conflicts have
been observed.
     On one machine, the second port always conflicted with something (though
     it's  not clear what) and caused strange results.  Disabling
the second
     port in the kernel config allowed the other three  ports  to
function correctly.


OpenBSD      3.6                          August      7,     1994