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>From [EMAIL PROTECTED] Thu May 14 15:16:21 1998
Date: Thu, 14 May 1998 07:16:27 -0700 (MST)
From: Bob Nielsen <[EMAIL PROTECTED]>
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To: "Breathnach, Proinnsias (Dublin)" <[EMAIL PROTECTED]>
Cc: "'debian-user@lists.debian.org'" <debian-user@lists.debian.org>
Subject: RE: V.90 modem recomendation
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On Thu, 14 May 1998, Breathnach, Proinnsias (Dublin) wrote:
> c) If you have a 386SX and an external 56K Modem you will NOT get a
> better connect than 9600bps due to the fact that the computer will only have
> an old INS 8250 UART. - even if the modem had a UART (which would be a
> redundancy) you will only get the throughput of the *slowest* part of the
> system.
>
> As always I'm open to contradiction on any points made here :)
Well, as long as you asked--
I've never seen a 386sx with an onboard serial port, but have successfully
used serial cards with 16550A uarts at rates above 9600 baud in a 386sx,
as well as a 286. IIRC, only 8086/8 types are limited to the 8250, and
that is only because of a bug in the chip design which was corrected in
the PC and XT bios, making them incompatible with the 16450 or 16550.
Bob
----
Bob Nielsen Internet: [EMAIL PROTECTED]
Tucson, AZ AMPRnet: [EMAIL PROTECTED]
http://www.primenet.com/~nielsen
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OK, you've got me there on the fact that I forgot about an add-on card !!,
almost all the 386 machines I have seen (I owned 4 so far - my current one is a
Dell 325SX - 8MB and a bit customised) have onboard serial ports based on the
8250 chipset, the 16450 you mention, while capable of higher rates still has
the smaller buffer which - if I'm right - can only reliably do about 19200bps ?
Anyway that's off the point - well spotted :)
All Generalisations are false - including this one :)
Proinnsias
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