🚀 go-pugleaf

In article <WERNER.96Mar18100602@asta.mc.ab.com>,
   werner@asta.mc.ab.com (tim werner) wrote:
>working.  The docs for the new card say that COM3/IRQ5 is really COM7.
>
>I don't know what that means.  Is it COM3 or COM7?  And how do I change
>which /etc files to reflect that difference.

Everyone has a different idea of what COM3 is.  IBM said it was a UART at 3E8H 
using IRQ4, but that conflicts with COM1's IRQ usage.  My hardware background 
says that COM3 is a UART at 3E8H no matter what interrupt it uses, which sort 
of fits in with the PS/2's idea of using IRQ5 (or was it 2/9?) for COM3.  
Windows seems to call the third UART it finds according to a specified search 
pattern COM3, no matter what its I/O and interrupt settings are.

As far as Linux goes, if it says that a modem at 3E8H using IRQ5 should be 
called COM7 and your modem is configured that way, then call it COM7.  SCO 
XENIX/UNIX wouldn't bother giving COMx names to serial ports anyway; tty2A, 
anyone?

>Furthermore, when I tried to disable the second serial port on my I/O
>card, and have both internal modems installed at the same time, there
>seems to be some kind of IRQ contention, even though I thought that was
>sorted out.

Please note that disabling a serial port doesn't always physically disconnect 
the interrupt request driver from the I/O bus.  Ideally, your card has a 
different jumper position for each potential interrupt and no jumper means no 
IRQ line connection.

It's also possible that the conflict is not with IRQs; it may be an I/O port 
conflict, an electrical load or interference problem on the I/O bus, etc.

>Here is my current configuration, I think:
>
>I/O card:
>   serial port 1:  COM1 / IRQ 4
                    ^^^^
Please don't call it COM1; call it 3F8.
>   serial port 2:  disabled (no jumper, instead of selecting COM2 or COM4)
>   printer IRQ:    7
>
>Internal modem 1 (14.4k):
>   COM3 / IRQ5
    ^^^^
3E8?

>Internal modem 2 (28.8k):
>   COM2 / IRQ3
    ^^^^
2F8?

Good luck!

--
            Geoffrey Welsh, Developer, InSystems Technologies Inc.
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  At home: geoff@zswamp.uucp or [xenitec.on.ca|m2xenix.psg.com]!zswamp!geoff
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