Date: Fri, 28 Jun 1996 13:27:19 +0300 (EET DST) From: "Andrew V. Stesin" <stesin@elvisti.kiev.ua> To: msmith@atrad.adelaide.edu.au (Michael Smith) Cc: Kevin_Swanson@BLaCKSMITH.com, hardware@freebsd.org Subject: Re: muliport boards - building a PPP dialup server Message-ID: <199606281027.NAA04222@office.elvisti.kiev.ua> In-Reply-To: <199606272343.JAA13951@genesis.atrad.adelaide.edu.au> from "Michael Smith" at Jun 28, 96 09:13:24 am
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Hello,
# > I want to add an ISA multiport serial card to this server and hang
# > up to 8 serial devices from it. Can you buy a multiport card that has
# > different speed limits on each port? For example, I'd like to have
# > maybe four high-speed connections up to 115.2KBps for user
# > connections, two ports that go to 57.6 KBps max and 2 ports that are
# > only 9600 baud.
#
# Don't bother; just get an 8-port "dumb" serial card with 16550's on it.
# You shouldn't have to pay more than a couple hundred dollars for it,
# and your system will handle a fair number of these ports flat out.
Seconded 100%. 16 ports are no problem. Speed limitations?
Read man stty :)
# > Basically, I'm going to be hanging some serial devices from this
# > that I don't need a fast connection for. If I want some ports to go up
# > to 115.2, do they all have to?
^^^^^^^^^^^^^^^^^^^^ No.
# > I'm looking to save some money if possible.
8x16550 IS The Cheapest Working Solution.
# > I've seen that some people have have used Digi PC/8 boards for this
# >type of thing? Digi also has "intelligent" models (PC/Xe, PC/Xr,
# >PC/Xem) that have a front-end processor and don't require an interrupt
# >on the computer? Has anybody gotten these "intelligent" boards to work
# >with freebsd 2.1?
#
# Of course, but any "intelligent" serial board will conflict with your
# "save some money" requirement; the cost per port is over double that
# of a "dumb" card, and in your case it's not warranted.
Not to mention the fact -- at least some models of
Digiboard have a speed limit of 57600; and despite
of their intelligence, I can't tell for sure that 16port Digi
really saves you so much CPU compared to 16x16550.
(Don't know is it a driver problem; but I have seen
a situation recently, when people (using BSDi) are
going back to FIFOed 16550s from Digiboard, because
of... CPU limitations).
#
# > Kevin_Swanson@BLaCKSMITH.com
#
# --
# ]] Mike Smith, Software Engineer msmith@atrad.adelaide.edu.au [[
# ]] Genesis Software genesis@atrad.adelaide.edu.au [[
# ]] High-speed data acquisition and (GSM mobile) 0411-222-496 [[
# ]] realtime instrument control (ph/fax) +61-8-267-3039 [[
# ]] Collector of old Unix hardware. "Where are your PEZ?" The Tick [[
#
--
With best regards -- Andrew Stesin.
+380 (44) 2760188 +380 (44) 2713457 +380 (44) 2713560
"You may delegate authority, but not responsibility."
Frank's Management Rule #1.
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