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From: dale@interlan.Interlan.COM (Dale B)
Newsgroups: comp.sys.ibm.pc.hardware,comp.sys.ibm.ps2.hardware
Subject: Re: Ethernet boards
Message-ID: <1990Dec5.164716.26717@interlan.Interlan.COM>
Date: 5 Dec 90 16:47:16 GMT
References: <1990Dec3.145208.25230@ugle.unit.no>
Reply-To: dale@interlan.interlan.com
Organization: Racal InterLan, Inc., Boxborough, MA (1-800-LAN-TALK)
Lines: 25

In article <1990Dec3.145208.25230@ugle.unit.no> heidnes@spurv.runit.sintef.no (Hans Eidnes) writes:
>A hardware question for those who are familiar with different ethernet
>adapters on the PC or PS/2.
>
>Do these four cards handle multicast packets differently in hardware? 
>
>3c523     (MCA)
>ni9210    (MCA)
>ni5210    (ISA)
>wd8003e   (ISA)
>
>- Hans Eidnes                         e-mail : heidnes@lise.unit.no

The question is not real clear, but I believe the answer is yes.  I think the
wd8003 & 3c523 use the Nat. Semi. 8390 NIC Lan chip, while the ni9210/5210 use
the Intel 82586.  The 8390 uses a 64 bit mask to imperfectly filter multicast 
addresses from the 6 MSBs of the CRC of the address.  The 82586 takes a list
of multicast addresses to be accepted.   I've always thought the 82586 did
perfect filtering, but re-reading the data book indicates I may have wrong.
Apparently the 82586 generates a 64 bit hash table from the address list and
uses bits 2-7 of the CRC to filter.
BTW often drivers using the 8390 implement perfect filtering in the
driver code and drivers using the 82586 generally do not.

		Dale