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From: scotty@l5comp.UUCP
Newsgroups: comp.sys.amiga
Subject: Re: Comments/questions on fast directory listings
Message-ID: <125@l5comp.UUCP>
Date: Thu, 14-May-87 09:59:22 EDT
Article-I.D.: l5comp.125
Posted: Thu May 14 09:59:22 1987
Date-Received: Sat, 16-May-87 14:42:04 EDT
References: <6561@amdahl.amdahl.com>
Reply-To: scotty@l5comp.UUCP (Scott Turner)
Organization: L5 Computing, Edmonds, WA
Lines: 26
Keywords: dir fast speeddir eless directory listing

In article <6561@amdahl.amdahl.com> kim@amdahl.amdahl.com (Kim DeVaughn) writes:
>As you pointed out, the drive motor for df1: does not turn off after
>doing a "dir".  It *does* turn off though after doing a "copy dfd1:foo ram:",
>or similar command.  Is it any "file system write" that deselects the drive,
>or what?
Kim, have you studied Leo's use of the dos packets to request direct disk I/O?
It kinda looks like it might do it, but I'm still studying what he has done
there myself.

>Also, it is interesting that after installing speeddir, the little power
>LED (not the drive LED) blinks alot when doing a "dir", or "copy" command.
Many people are not aware that the "power LED" is actually under CPU control.
One hack I made using this fact was to use it in a rebuilt MicroForge hard disk
driver so that the power LED became a "hard disk activity LED" :). However, it
is more often used for debugging code that can't use any "high level" means of
communicating with the programmer. A perfect example would be in a IRQ service
routine where you can't risk any I/O thru the system. I'd type in the manual
reference for flipping the LED, as per Leo's request, but my hardware manual is 
currently 20 miles away...

Scott Turner

-- 
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[ BCPL? Just say *NO*! ] (I don't smoke, send flames to /dev/null)