[comp.sys.3b1] cmb drivers support passed 6 EIA ports.

beyo@beyonet.UUCP (Steve Urich) (02/21/91)

	Hello,
		I am a recent addition to the comp.sys.3b1 group and
the world of netnews. Finally got my groups corrected at the sending
end of the modem. :-) Recieving comp.*.3b1 now with conviction!

		I have the hardware ability to go past 6 ports on my
3b1, only to be held up by the fixed binary drivers for the RS-232/EIA's.
The drivers are limited to a maximum of 6 tty's.(+ tty000). I can't
make the software recognize the other 6 ports. :-( Does anyone know
how to change this or know someone with more then 6 ports on a 3b1?
Please reply thanks.

		Thanks again to all that tried to help and gave me
some light at the end of the tunnel...

					Steve WB3FTP

					dsinc!wells!beyonet!beyo

botton@i88.isc.com (Brian D. Botton) (02/22/91)

In article <148@beyonet.UUCP> beyo@beyonet.UUCP (Steve Urich) writes:
>
>	Hello,
>		I am a recent addition to the comp.sys.3b1 group and
>the world of netnews. Finally got my groups corrected at the sending
>end of the modem. :-) Recieving comp.*.3b1 now with conviction!
>
>		I have the hardware ability to go past 6 ports on my
>3b1, only to be held up by the fixed binary drivers for the RS-232/EIA's.
>The drivers are limited to a maximum of 6 tty's.(+ tty000). I can't
>make the software recognize the other 6 ports. :-( Does anyone know
>how to change this or know someone with more then 6 ports on a 3b1?
>Please reply thanks.
>

  I tried sending e-mail a couple of times, but it kept getting bounced.

  It is not a simple fix to allow more then 6 expansion ports.  There are some
hardcoded arrays that are easy to fix, but there are a few other things.
Each port gets its own interrupt service routine, which is fairly simple
and easy to duplicate from the source.  Unfortunately there appears to be
a problem with tty structures.  Informed sources have told me that the kernel
doesn't keep a tty structure pool.  Instead, it allocates a hard coded
number of structures that matches the number of supported ports, in this case
7.  Other drivers that need tty structures are required to allocate their
own.  Since the cmb.o driver doesn't allocate these structures, the kernel
has to be modified to support more.
  I wish I had the time to help, but I already have way too many things going
on.

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