From: mju@mudos.ann-arbor.mi.us (Marc Unangst)
Subject: Re: Adaptec 1740 modes.
Date: Wed, 2 Sep 1992 04:56:43 GMT
Organization: The Programmer's Pit Stop, Ann Arbor MI

In article <9209010953.AA25837@dynamix.com> david@dynamix.com (David L Jarvis) writes:
>well for someone who spent a couple of hundred lines telling me how
>atrocious my correspondence skill are, I'd have to say that "Aiiieee!"
>ranks right up there with AIN'T ... 

I also sent that to you in e-mail, because spelling flames are not
appropriate for general Usenet consumption.

Ever hear of "humor?"  Or "conversational English?"

>(but nice try at the cheap shot tho, you're getting better with each try)

Huh?  All I implied that your memory might be somewhat less than
perfect, and that you might have mistranscribed something if you
copied it from memory.  This is a cheap shot?

>ANYONE on the net - check it out for yourself!!!   Call SCO or get SCO
>magazine and verify it ... (repeated for those of you who failed to read

I wouldn't call SCO Magazine a source of gospel about SCO Unix.  The
second-line and third-line support technicians at SCO are generally
more trustworthy (the first-line technicians, unfortunately, do the
same thing I could do myself -- look up my problem in the SCO
Information Tools database).

>so how about it Marc, again I'll challenge you, give SCO a call and ask
>them what they suggest for making the change ... and then post the response
>you get ...   

Well, I haven't called SCO SofTech yet, mostly because I have real
work to do, and my real work consists of answering questions for
paying customers, instead of answering questions for the net.  But if
I get a free moment I'll see about calling them.

>(what Marc said doesn't make sense to me, because anyone who knows the
>system would know that eiad is just the enhanced mode of the ad driver, so
>I see no confusion there, but I'm open to discussion on it)

The problem is that, the way the ID system is set up, each device
driver is supposed to have system-dependant information about the
driver configuration (IPL level to run at, IRQ lines used, I/O
addresses used, and so forth) in /etc/conf/sdevice.d/name_of_driver.
i.e., the sio driver info is in /etc/conf/sdevice.d/sio, the ad driver
info is in /etc/conf/sdevice.d/ad, and so forth.  When idbuild is run,
it concatenates all of the files in /etc/conf/sdevice.d into a master
/etc/conf/cf.d/sdevice file.

The idea is that each driver can be installed, deinstalled, and
modified in a modular way without modifying files that the other
drivers know about.  There's none of the ugliness associated with the
Xenix link_xenix shell script, or with BSD-style kernel configuration.

The "correct" way to turn a driver off is to change the second field
of its sdevice file from a Y to an N.  Similarly, the correct way to
turn a driver on is to change the second field from an N to a Y.  You
are not supposed to add entries to an sdevice file for drivers other
than the one with the same name as the sdevice filename.

Now, let's say that you do things SCO's way, and change the instances
of "ad" to "eiad" in /etc/conf/sdevice.d/ad.  The next time you build
your kernel, the ad sdevice file will get concatenated with all the
other files in /etc/conf/sdevice.d, including
/etc/conf/sdevice.d/eiad, which is where the eiad-related
configuration is *supposed* to go.  Since SCO ships SCO Unix with the
eiad driver turned off, there will be no problems; the idbuild script
doesn't know where the individual lines in the sdevice file came from,
and so it won't notice that there is no "ad" line and that there are
two "eiad" lines, since the second one is disabled.

However, let's now say that you get an SLS from SCO that includes a
new "ad" driver.  Let's say that this driver fixes a problem with the
Adaptec driver preempting another driver because the Adaptec driver
was running at the wrong IPL level.  To change the IPL level, you have
to modify the sdevice file; most likely, the SLS will overlay your
existing "ad" sdevice file with the new one.  This is completely
legal, since the SLS isn't changing any other drivers -- or is it?
Since you put the eiad sdevice info in the ad sdevice file, you've now
lost your eiad sdevice info.

If, on the other hand, you put the sdevice info for the eiad driver
where it belongs -- in eiad's sdevice file -- you will have no
problems.

>well your .sig sure gives us some insight into YOUR computing philosophies
>tell me, you would happen to be a college student would you?

Nope.  Actually, I'm a senior in high school.  But what does my age
have to do with this?

-- 
Marc Unangst                | Real men don't use Windows.  Real men use X. 
mju@mudos.ann-arbor.mi.us   | Only a real man would use a GUI where the
                            | shift keys after "Alt" are "Super" and "Hyper."
Newsgroups: comp.unix.xenix.sco