Path: utzoo!attcan!ncrcan!moegate!soley
From: soley@moegate.UUCP (Norman S. Soley)
Newsgroups: comp.protocols.tcp-ip.ibmpc
Subject: Re: Interrupt vectors for PC Ethernet cards
Message-ID: <396@moegate.UUCP>
Date: 17 Jun 89 20:27:41 GMT
References: <782@omen.UUCP> <8906121543.AA25731@vax.ftp.com> <15853@vail.ICO.ISC.COM>
Reply-To: soley@moegate.UUCP (Norman S. Soley)
Organization: Ontario Ministry of the Environment
Lines: 26

In article <15853@vail.ICO.ISC.COM> dougm@ico.ISC.COM (Doug McCallum,violet,114,) writes:
>In article <8906121543.AA25731@vax.ftp.com> jbvb@VAX.FTP.COM (James Van Bokkelen) writes:
>>The only AT-bus cards that hack interrupts greater than 7 are the 3Com
>>3C505 and the other "16-bit AT-bus" cards (Gateway, IMC and Tiara that
>>I know of, maybe others).  3Com's PCS/TCP, our PC/TCP and NRC Fusion
>
>While most don't support the signals for the second PIC, IRQ 2 (the IRQ the
>second PIC is chained off of) can be used and will give an interrupt in
>the upper range.  This gets back an IRQ that people tend to think is missing
>on an AT.  A lot of the 8-bit boards do support IRQ 2.  This helped some
>of our 386/ix customers who thought they were out of IRQs.

I've seen this discussed before. In fact I'm using this hack on one of my
machines. It seems to work but I'm concerned that it may not be reliable.
Can anyone who really understands how the PIC's work comment on the 
implications of strapping the hardware to IRQ2 and calling it IRQ9 in
software? 

Also it doesn't do you any good on the DOS side of things if you're using
a commercial package, none of them try to do this.

-- 
  Norman Soley - The Communications Guy - Ontario Ministry of the Environment
soley@moegate.UUCP  or if you roll your own:  uunet!attcan!ncrcan!moegate!soley
   The Minister speaks for the Ministry, I speak for myself. Got that! Good. 
     Stay smart, go cool, be happy, it's the only way to get what you want