Date: Tue, 9 Apr 1996 18:04:34 -0700 (MST) From: Terry Lambert <terry@lambert.org> To: Brett_Glass@ccgate.infoworld.com (Brett Glass) Cc: terry@lambert.org, questions@FreeBSD.org Subject: Re: Artisoft AE-3 Ethernet card: How to use large buffer? Message-ID: <199604100104.SAA06406@phaeton.artisoft.com> In-Reply-To: <9603098290.AA829087812@ccgate.infoworld.com> from "Brett Glass" at Apr 9, 96 02:04:51 pm
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> > You could always try it. I don't think it will work, since it's > > unlikely to have compatable gate array settings. > > I'm not sure, but I believe that the internal buffer is not directly > accessible on NE2000 clones. As I understand it, the RAM is accessible via > programmed I/O after setting a pointer register. (This is one of the common > criticisms of the architecture: PIO isn't quite as fast as shared memory.) > > > You need to set mem_end to mem_start + 64k. This should be done in > > whichever probe routine is coming true. > > Aren't the mem_end and mem_start parameters used for cards that have shared > memory (rather than a PIO/counter scheme)? > > > This assumes that, unlike some cards, there is not only an 8k window > > to get at the memeory (in which case you want to leave it alone). > > Again, I'm not certain, but I believe that access to the buffer does not > take place via a memory window at all. I was reading from the comments in the /sys/i386/isa/if_ed.c. Search for the string "mem_end". I think you might be looking at the 3COM specific code? Terry Lambert terry@lambert.org --- Any opinions in this posting are my own and not those of my present or previous employers.
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