Serial port question

From: Les Klassen Hamm <leskh_at_no.spam.please>
Date: Thu Jun 03 1999 - 01:27:36 CST

I'm setting up an older 486 with linux, and I have an external modem for
it, and just discovered that the serial ports on the VESA Super IO card are
slow (16450 UARTS). So I presume I need to add a real one.

I have the manual for the Super I/O card, and can disable com2 on it.
Then boot messages say "ttyS00 at 0x03f8 (irq = 4) is a 16450" and the
mouse continues to function on com1 (okay, /dev/ttyS0)

I have an 8bit I/O card with a 16550 UART sitting around, but without
manual, so the jumper settings are a guess. When I put the card in, the
boot messages say
ttyS00 at 0x03f8 (irq = 4) is a 16450
ttyS01 at 0x02f8 (irq = 3) is a 17550A

This looks good, but the mouse no longer functions, and I still can't get
at the modem. If I try to talk to the modem (either in minicom or a pppd
chat script), the TR light comes on, but no data is sent or received, and
thus the modem is not initialized. Is something lying to me? Are the IRQ's
not what they are reported as? Am I missing something obvious? (I did test
the modem and the cable at reduced speed on the 16450 ttyS1 on the super
I/O card before disabling it, and then it worked fine (at 9600!).

Or if you have no better ideas, does anyone have an I/O card with all the
jumper markings clear or with a manual that they want to get rid of?

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Received on Thu Jun 3 01:27:36 1999

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