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From: terry@cs.weber.edu (Terry Lambert)
Newsgroups: comp.os.linux.misc,comp.unix.bsd
Subject: Re: Notebook - PCMCIA
Date: 15 Mar 1994 01:14:54 GMT
Organization: Weber State University, Ogden, UT
Lines: 53
Message-ID: <2m326e$ipu@u.cc.utah.edu>
References: <2lm8ok$ssr@news.nynexst.com> <2lp2t9$r73@u.cc.utah.edu> <2m1bfj$ptg@rzsun02.rrz.uni-hamburg.de>
NNTP-Posting-Host: cs.weber.edu

In article <2m1bfj$ptg@rzsun02.rrz.uni-hamburg.de> andrae@rzdspc2.informatik.uni-hamburg.de (Caroline Andrae) writes:
>|> >Have you tried to put your notebook on a network with a PCMCIA ethernet
>|> >card?

ME> Works great; all you need is a PCMCIA enabler shim, which is very few lines
ME> of code to write, especially if you have doc's for PCMCIA.  Most of the
ME> network cards are NE2000 compatible.  Should take you half an hour.
ME> 
ME> It also works with anything else PCMCIA if you code things right (or one
ME> network card exactly if you do it wrong), including FAX modems and SCSI
ME> interfaces for things like tape drives.  8-).

>Could you please explain, or post the thing you wrote?

I can't post code for well known reasons, or we'd have had Sun-style
shared libraries in June of 93 (...er; without C++ support) and have
Streams and run Xenix and UNIX binaries today, etc.

I can tell you what I did to get the information needed, though.

The first thing I did was notice that Kurt Mahan wrote something like
it for UnixWare, which meant it was possible.  8-).

Then I bought a copy of "Undocumented DOS, Second edition" and started
disassembling the PCMCIA BIOS calls documented there to see what they
did to do PCMCIA'ish things (this is the same book that talks about
the EISA bus signature word for identifying EISA bus machines to turn
off bounce-buffers, which are not applicable to EISA).  This will get
you enough to attach cards on startup, although there's little else you
can do in line with the standard.

Most recently, I've called up Intel and asked for documentation for the
chipset.  Each chip can handle two cards, and most machines have only
one chip.  The chip lets you map an interrupt and up to four address
windows onto what it expects to be an ISA bus on the other side.  You
get to pick where they go.

An attach is a determination of device type, a lookup of the driver, and
a mapping matching the driver settings for the device.  The attach should
be done before the probes go.  This is sufficient to get most ethernet
cards for PCMCIA running, since they mostly all look like NE2000's.

I'll hack more on the thing when I get the Intel docs (thanks to Kurt
who pointed me at them) and can borrow the laptop again with a couple
of different types of cards.  I suspect getting a SCSI interface up will
be quite a chore for the attach requirements.


					Terry Lambert
					terry@cs.weber.edu
---
Any opinions in this posting are my own and not those of my present
or previous employers.