Path: utzoo!utgpu!jarvis.csri.toronto.edu!rutgers!sun-barr!texsun!pitstop!sundc!seismo!uunet!mcvax!kth!draken!tut!santra!tukki!makela
From: makela@tukki.jyu.fi (Otto J. Makela)
Newsgroups: comp.unix.microport
Subject: Re: Using AST 4port or clone on uPort
Summary: Gotcha !
Keywords: AST 4port ttypatch
Message-ID: <705@tukki.jyu.fi>
Date: 15 May 89 01:17:44 GMT
References: <701@tukki.jyu.fi>
Reply-To: makela@tukki.jyu.fi (Otto J. Makela)
Organization: Grand Hall of Justice, Mega-City One
Lines: 32

In article <701@tukki.jyu.fi>, makela@tukki.jyu.fi (Otto J. Makela) says:
>I recently got a (supposedly accurate) clone of a AST 4port card. [...]
>The uPort manual says to use for example
>	ttypatch -t6 -i7 -a416 -n4 -v0x1bf -m0
>and to take care that the card is in the enhanced (enchanted ?)
>mode and that "shared interrupts are disabled (SW 3-3)".
>The enhanced mode is easy, the opposite is that the card is COM1,
>COM2 and two non-standard ports.  But I'm not sure about the
>shared interrupt stuff (disturbingly, the card I have has only one
>DIP switch) ?
>[...] (the machine has both COM1 and COM2 on the mother board).
[plus what happened, how it didn't work...]

I now know why it does not work.  The small print on the release document
states that IRQ's cannot be shared by different cards.  When I disabled
the motherboard COM2 and used IRQ3, all worked ok.  The big question now
is, how does one define "different cards" ?

I have a card which has 8 RS-232 ports.  All these ports are identical with
the basic PC RS ports.  This 8fold monster can be configured to be COM1, COM2,
COM3, COM4 + 4 nonstandard ports, or as 8 nonstandard ports with a few
variations.  Each port can be set to produce IRQ3 or IRQ4.  I guess they are
logically on "different cards", since they are totally independent ?

The question about shared interrupts still stands.  What do the card settings
have to do with the interrupt mechanism ?

Otto J. Makela (with poetic license to kill), University of Jyvaskyla

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